'You can do what you want with your husband when you're alone with him. You owe him anything and everything. But only him.

'You need to fulfill his every wish. You can wear whatever you want under your sitar and burqa. Garter belts, fishnet stockings, anything your husband might like.

'Do you like pretty lingerie, baby?'

It makes the skin crawl just reading these slimy words, intended by a high-ranking ISIS jihadi to seduce a young western woman into joining him in Syria as his wife.

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'Metrosexual jihadist': Preening Abu Bilel sent Melodie pictures of himself 'puffing out his chest' with an M4 assault rifle 'slung across his shoulder', not knowing she was actually a French journalist

Deception: Anna Erelle, which is not her real name, spent a month leading Bilel on in the guise of a 20-year-old Muslim convert from Toulouse

'Evil genie': Bilel told Melodie 'You're my jewel, you're pure' as he tried to seduce her

But the 20-year-old Muslim convert Abu Bilel thought he was sweettalking on Skype was actually a French journalist pretending to be in love with him.

The reporter Anna Erelle, the pseudonym under which she has published a book about her month-long 'relationship' with Bilel, also uncovered the 38-year-old militant's embarrassing attempts at seduction.

Published tomorrow in the UK, 'In the Skin of a Jihadist: Inside Islamic State's Recruitment Networks', follows Bilel's courtship of 'Melodie', the name Anna gave to her young character from Toulouse.

It all started when Melodie, a profile Anna had used before to explore the world of cyber jihadis, absent-mindedly shared a video of Bilel's in which he poses in fatigues with an M16 rifle boasting about how it had been stolen from a marine in Iraq.

In the footage Bilel, himself originally from France, took off his Ray-Bans to reveal eyes plastered with eyeliner just like Melodie's - a trick allegedly borrowed from Afghan soldiers to stop them tearing up when exposed to smoke.

Within hours the highest-ranking French ISIS fighter in Syria, a man claiming to be a jihadist for 15 years who was close to the group's leader Abu Bakr al-Baghdadi, had messaged her.

'Salaam alaikum, sister. I see you watched my video. It's gone viral - crazy! Are you Muslim?

'What do you think of mujahideen?

'Last question: are you thinking about coming to Syria?'

Melodie humours her new suitor, who sends a disbelieving Anna a picture of himself 'puffing out his chest' with an M4 assault rifle 'slung across his shoulder'.

Having yet to see Melodie's face, Bilel the 'honey-tongued', 'evil genie' begs if he can 'be [her] boyfriend'.

Bilel is soon pressing Melodie to speak to him on Skype until a couple of days after he first message her, they are looking at each other across a computer screen, her face covered by a veil but his eyes 'still accentuated by dark eyeliner...smoulder[ing] as he gazed at the young Melodie, as if trying to cast a spell.'

'A lot of women fantasise about us; we’re Allah’s warriors.'

'I kill anyone who tries to prevent Islam from dominating the world.'

'You’re my jewel, you’re pure.'

High-ranking: The 38-year-old Bilel was ISIS' highest ranking French jihadi in Syria with close ties to leader Abu Bakr al-Baghdadi

Creepy: As Melodie, Anna was subjected to Bilel's 'pathetic techniques of seduction. It felt like being on a dating website "adoptajihadist.com"'

In between boasting about his status as a 'prominent mujahid', and impatiently awaiting the arrival of 'American cargo' with foreign chocolate bars in it, Bilel's twisted day job as a murderous militant is mentioned almost as casually as if he were a normal boyfriend with a nine-to-five job.

He calls Melodie 'baby' and often speaks to her sitting along in an internet cafe with his hair 'slicked back with gel', causing the writer to remark: 'This militant looked more like a pretty boy obsessed with is own “hotness” than a solider'.

By the time of the creepy lingerie discussion, Anna writes: 'perhaps Melodie should send her sweetheart some anti-wrinkle cream to maintain his "metrosexual jihadist" looks.'

With a photographer, Andre, off camera capturing pictures of Anna as Melodie talking to Bilel, her Romeo tells her at one point: 'You look curvy, which I like. And, as I said before, I'm good-looking.'

Anna writes: 'From where he sat, Andre couldn't see Bilel, who was slowly licking his lips.

'...Bilel easily shifted from boasting about his gruesome "exploits" to deploying his pathetic techniques of seduction.

'It felt like being on a dating website "adoptajihadist.com".'

Claiming he has 'had the judge draw up some papers', meaning he and Melodie will be married as soon as she sets foot in Syria, Bilel asks her what she wants for a dowry.

'I’m Tony Montana here, except I don’t deal in drugs but in faith. ISIS is loaded.'

An argument about whether Melodie is a virgin brings the warning from Bilel: 'I’ve really put myself out there for you, so don’t make a fool of me. Be strong; come to Syria. You’re a real lioness, my wife.'

The needy jihadi is now pestering Anna constantly, on her fake Facebook and Skype accounts and a separate mobile phone she has for his calls and texts.

'You’re my jewel, and Raqqa is your palace,' he tells her.

Clever trick: Anna had a special phone for Bilel's calls and messages and managed to convince the lovesick jihadi she was Melodie for a whole month

'You’ll be treated like a princess...Before I only had work, but you’ve given me another reason to live.

'We should talk about our wedding night…I hope you have some pretty underthings for that special night.'

But things turn sour when Anna travels to Amsterdam as Melodie bringing with her her non-existent 15-year-old friend 'Yasmine', who also wants to be a jihadi bride.

When she expresses reservations about flying to Turkey so she can make her way to Syria and be with Bilel, he rants: 'From now on you're going to shut up.

'I'm part of a terrorist organisation. You can't talk to me like that. Don't you know who I am? I command 100 soldiers every day.

Scary: Anna's book ends with a fatwa being taken out against her, as she is branded 'more impure than a dog'

'I haven't even told you a quarter of the truth. I'm wanted internationally; that's why I can't even go to our cities in Turkey.

'I can only travel to Iraq. I’m 38, you brat, and you and your friend can’t bring me down.

'You don't know who I am. You'd better tread lightly.

'Where are you, you little bitch? I swear to Allah, you’re going to pay’

'You wanted to make an idiot out of me; I’ll make you pay. ROFL.’

The sweet would-be husband who packs his messages with emoticons and 'LOL' acronyms like a lovesick teenager, turns out to be a monster who already has three wives, Anna finds out later.

Her initial ordeal finishes when she cuts off all contact with Bilel, who is then reported as having been killed, though it remains unclear to this day whether he is still alive or not.

But for Anna, the potential dangers of what she has got herself into don't stop there.

The book finishes with the journalist uncovering a video showing her wearing Melodie's veil on her couch, on top of which these chilling words flash on screen:

'My brothers from around the world, I issue a fatwa against this impure person who has scorned the Almighty. If you see her anywhere on earth, follow Islamic law and kill her.

'Make sure she suffers a long and painful death. Whoever mocks Islam will pay for it in blood. She's more impure than a dog.

'Rape, stone and finish her. Insha'Allah [god willing].'

Today, the real Anna lives under police protection in Paris. She told The Observer she has no regrets for what she did.