Decided to be a priest aged just 15, but remained close to best friends

Friends also remember his dedication to the church from an early age

But the relationship ended - and a little later Jorge entered the seminary

Friends say the teenager was 'crazy' about the girl, who was 'very pretty'

They reveal how Jorge fell in love with a girl - and had a brief relationship

Pope Francis was a red-blooded teenager who enjoyed the company of pretty girls, took part in pranks on teachers, and was smitten with a beautiful 16-year-old brunette, MailOnline can reveal.

Former schoolmates of the 78-year-old Pontiff, who were in his 10 Muchachos (or Ten Lads) gang of friends, have spoken for the first time about the young Jorge Bergoglio's high school days.

And they revealed a studious yet normal young man who knew how to 'smart talk' the ladies, and who 'if a girl passed by who he thought was pretty... would say so'.

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Great mates: The young pontiff - circled - pictured with classmates during the 1950s, including his best friends Alberto D'Arezzo, fourth from right, and Oscar Crespo, fifth from left

Calling: Pope Francis, who was then known as Jorge Bergoglio, pictured close up, right, was elected to the role at the head of the church two years ago - more 50 years after he entered the seminary

Roots: Despite the thousands of miles and vastly different lives which separate him from his boyhood friends, they are still close - and now Alberto and Oscar (left to right) have shared some of their memories

Bergoglio belonged to a gang of ten boys who would try to pick up girls at dances and discotheques, while their mischievous antics left their teachers exasperated - and once got the future pope a reprimand from the school's headmaster.

And amid constant speculation about whether any woman might have once stole the Holy Father's heart, his best friends revealed that there was ever only one contender - a girl called Tonecha who 'drove him crazy'.

The pair, who met at a dance in the Chacarita district of Buenos Aires, ended up going on several dates during which they 'must have kissed', according to his pals.

Oscar Crespo, who has remained friends with Bergoglio and recently met with him at the Vatican, said of Tonecha, who lived in the neighbouring Villa Ortuzar district: 'She was a really pleasant girl, with olive skin and brown hair, very pretty.

'She talked a lot, the complete opposite of Jorge. She was a year younger than him. He would see her at the dance and never stopped talking about her, saying how beautiful he found her.

'He eventually managed to chat up Tonecha and on their first date took her to the cinema.

'They went on a couple of other dates and then the thing fizzled out. It was a brief relationship, it ended and they said goodbye.

'I don't know who called it off. But Jorge already felt a calling to the priesthood and probably knew that it would never come to anything.

Much-loved: Pope Francis is now welcomed by adoring crowds where ever he visits

Younger years: Jorge grew up in Argentina, one of five children (pictured left with brother Oscar) and is said to have done well at school

Friends: He appears to have been a popular young man, and went around in a group of 10 called 'Los 10 Muchachos', or 'The Ten Lads'. Pictured here with Oscar second from left, Alberto fourth from right

Legendary: Oscar says the parties they used to throw - like the one which followed this invite - were unforgettable, and Jorge even once dressed up as a woman after the boys raided a cupboard

'I'm sure he kissed other girls, but he was discreet and didn't tell anyone. But Tonecha was the one who drove him crazy, he couldn't keep quiet about her.'

Oscar said they lost contact with Tonecha - which he believes was her nickname - and heard some years ago that she had passed away in her old age.

Tellingly, just months after their relationship ended Bergoglio made a decision, aged 17, to go to Catholic seminary and train to be a priest.

Until now very little has been written about Pope Francis' high school days, when he studied from the age of 12 at the Technical Industrial School No 12 (now No 27), in the Floresta neighbourhood, which specialised in chemistry.

Our house parties were unforgettable. One night, we raided my sisters wardrobe and all dressed up in women's clothes. I put on a cloak to be Zorro, and Alberto and Jorge dressed up as a woman Teenage friend Oscar Crespo

But speaking exclusively to MailOnline, Bergoglio's best friends Oscar and Alberto D'Arezzo, both 77, agreed to lift the lid for the first time on the Pontiff's carefree teenage years.

The 'inseparable' friends, who have remained close up until today, were in the same class at school and would meet up every morning for coffee at the nearby El Tuyense bar before lessons.

After school they would sometimes play billiards at a local bar, or study together at Jorge's home, while at weekends they would often meet up at Oscar's where they would throw lively parties, or get ready to go out dancing.

One invitation made by the group, which Alberto kept, reads: 'The 10 Lads invite you to a dance meeting to take place on Sunday 22nd, 1955, in Salon Bel-Sito, 9pm.'

Oscar, who went on to be a food technician for bubblegum company Bazooka, said the friends saw a side to the future pope which nobody knows about.

He said: 'Jorge was always one of us, a part of the group, he did everything that we did. We had a lot of fun together. We were a bunch of guys getting to know ourselves, the world, and girls.

'Our house parties were unforgettable. One night, we raided my sisters wardrobe and all dressed up in women's clothes. I put on a cloak to be Zorro, and Alberto and Jorge dressed up as a woman. We had no make-up so they painted their face with burned cork.'

Memories: Oscar recalled: 'Jorge was always one of us, a part of the group, he did everything that we did. We had a lot of fun together.' Pictured: The whole school in the Floresta neighbourhood

Residence: The Pope's childhood home - which is now marked with a plaque. His father Mario was an accountant employed by the railways and his mother Regina Sivori, according to the Vatican's website

Education: The school specialised in chemistry, and Jorge, circled, attended it from age 12 until he graduated as a chemical technician in 1958 - but chose to enter the priesthood instead

First autograph?: The boys signatures on the back of the picture (above), taken when they were 14

On Sunday nights, the group went out to dance jazz and tango in a club in the Chacarito neighbourhood because it was 'full of pretty girls'.

Alberto remembered: 'We would spend hours getting ready, combing our hair, sharing my bottle of Polyana deodorant, making ourselves look smart in shirts and formal suits. Of course we wanted to be very well dressed.

Although Jorge was one of us, we also felt he had something different. He already had inside of him a vocation to care for people, to evangelise Oscar

'At the club, the boys would dance in the middle and the girls would sit around the sides watching us.

'If any of them liked one of us, they'd nod in our direction. If you liked her, you'd nod back, meaning you could invite her to dance. That's how it worked back then.

'We would try to impress, hoping to get a nod. Yes, Jorge would dance too. It was an embarrassment to leave the club without getting a dance. Sometimes we'd have to dance with an ugly girl just to say we danced with somebody.

'We all came prepared with cigarettes and mints in our inside pockets, so the girls wouldn't smell smoke on our breaths.'

Oscar said that while Jorge was more 'repressed' than the other boys, he wouldn't hide his attraction to the opposite sex.

Preening: Alberto, x, revealed: 'We would spend hours getting ready, combing our hair, sharing my bottle of Polyana deodorant, making ourselves look smart in shirts and formal suits'

Register: Few can have imagined when they entered Jorge's name and address into this handwritten register that he would one day be the head of the entire Catholic church

Letter: A month after his election, he sat down to write this note to his old friend Oscar

He said: 'We were all regular teenagers who wanted girls and wanted to have fun, and although Jorge was quieter and more reserved, he wasn't any different.

'If a girl passed by who he thought was pretty, he would say so.'

Ordained: A picture taken in 1973 of the then priest Jorge Mario Bergoglio, shortly after his 1969 ordination into the church

And according to Alberto, Bergoglio's celibacy vow after becoming a priest still didn't stop him looking.

He laughed: 'There was a time not too many years back when I joined Jorge, who was now the Archbishop of Buenos Aires, for a meeting with a female government official.

'She was a strong women with large breasts, and I noticed that Jorge couldn't stop looking at her cleavage, through the whole meeting.

'Afterwards I mentioned it to him and he just laughed.'

Oscar, who married wife Ruth in 1968, admitted it was much harder for a boy to date a girl in the 1950s, but it didn't stop the gang trying.

He said: 'There was much more control. The girls would turn up to the dance accompanied by their mothers or their aunts.

'We'd sometimes have to wait until they had gone outside to smoke a cigarette to make our move.

'Girls would often be chaperoned. There is a part of the front of houses in Buenos Aires called the "zagon", where you could managed to get hold of the girl after her mother had already gone inside.

'That's where most of the touches and kisses happened.'

At school, the future Holy Father was known as a serious, smart boy who studied hard and loved to read - but his gang's antics still landed him in hot water a number of times.

On one occasion, one member of the group secretly put a heavy iron weight in the briefcase of a particularly ill-tempered Chemistry teacher, causing an eruption of giggles when he went to pick it up.

Loyal: The Pope wrote this letter to a friend in prison during his time as a priest. From a young age, he encouraged people to join the church and became 'godfather' to many of his contemporaries

Unbelievable: His closest friends cannot believe his unexpected rise to the Vatican - but are very proud

And another time, after the arrival of a Spanish teacher that none of the pupils liked, Jorge was one of the group would signed a chalk-written statement on the blackboard demanding their old teacher back, an act of disobedience which earned him a headmaster's reprimand.

But there were also times when Jorge's calling to Christian ministry was evident from an early age.

Oscar remembered: 'In the second year our teacher of religion asked anyone who doesn't receive communion to stand up. I was one of those who got up.

'The teacher then said, "Your classmate Bergoglio is inviting you to take first communion and has offered to be your godfather".

During his first trip abroad to Brazil three million people turned out to see him, just to try to catch a glimpse of him, our best friend. I get goosebumps now just thinking about it, it is incredible, unbelievable Alberto D'Arezzo

'It was clear that it was Jorge who asked the teacher to do that. That Sunday we took communion at the San Jose de Flores Church near Jorge's house, and then he took us home to have lunch.

'He ended being the godfather to many young people, three people from the gang and at least three others that I know of, but probably many more. And he was only 14.'

On another occasion, Jorge, then 15, started to become worried about a classmate, Carlos Hector, who had suddenly stopped coming to school, so took Oscar and Alberto with him to visit the boy at his house.

Oscar recalled: 'We discovered that Carlos was in jail. His sister told us that he had been playing with the gun belonging to his dad, who was a policeman, when it accidentally went off and his friend was killed. The judge didn't believe his story and convicted him of murder.'

Bergoglio wrote a letter to Carlos and continued to communicate with him during the years he was in prison.

In a letter sent to Oscar, Carlos wrote how he misses the group's house parties, adding: 'I have read with great satisfaction Bergoglio's letter, and felt these were words that came from his heart. It's important to read the things about school, they are a treasure.'

Oscar said: 'Although Jorge was one of us, we also felt he had something different. He already had inside of him a vocation to care for people, to evangelise.

'We were the same age, but when we had personal problems, even it was just a fight with our dad, he was the one we'd go to for help. He always knew the right thing to say to us.'

Close: Oscar with the Pope - then the Archbishop of Buenos Aires - six years ago. Their friendship has kept strong for more than six decades

Sustained: Oscar found the time to pop in on his old friend when he visited Rome last year (pictured) - with the Pope saying hr would be hurt if he didn't stop in. Alberto now plans to visit his old friend as well

It was in 1952, while Jorge and Oscar spent four months working at the Hichkethier-Bachmann laboratory near Santa Fe, 300 miles north of Buenos Aires, a work placement arranged by their school, that the future Holy Father decided that his future was in the Church.

Oscar said: 'I was the first person he told. He said, "I'll finish secondary school with you, but I won't be chemist, I'm going to be a priest".

'I asked why, and he said it was because he wanted to minister to the poor, to go into the slums and preach the Word of God. And that was it. After that he never looked back.'

Bergoglio finally joined the seminary of Villa Devoto in 1957, before deciding to become a Jesuit.

On March 11, 1958, aged 21, he entered the Society of Jesus in Cordoba, central Argentina, beginning a course of study lasting 14 years.

He was ordained to the priesthood in 1969, rising to become Archbishop of Buenos Aires in 1998.

For Oscar and Alberto, seeing their best friend rise to become the head of 1.2billion Catholics, one of the most famous people on the planet who will go down in history, is still difficult to take in.

When Pope Francis found out that Oscar was planning to visit Rome last October, he called him and told him 'I'll be very angry if you don't come and visit me'.

And on New Year's Eve last year, the Pope called Alberto's home to send his best wishes, although he wasn't home and he ended up speaking with his wife.

Alberto, who plans to visit Francis at the Vatican this year, said: 'During his first trip abroad to Brazil three million people turned out to see him, just to try to catch a glimpse of him, our best friend. I get goosebumps now just thinking about it, it is incredible, unbelievable.

'He will make for himself a great history, I'm sure of it. Every pope before him as been so distant. But now people are emotional because they have a man who seems so normal and understanding.