Most men would expect a swift slap in the face if they asked their partner to get a boob job.

But Ivan LeCasque loves big busts so much that he's written a book teaching men how to persuade their partners to supersize their breasts.

The 59-year-old wrote the $17 (£10.80) Convince Her To Get Bigger Breasts Manual with the help of girlfriend Victoria - who has had her bosom enhanced from a 26D (26D UK) to 26O (26K UK) over the course of their relationship.

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Ivan LeCasque loves big breasts so much so that he has written a book teaching men how to convince their partners to get breast augmentations. The 59-year-old lives in Miami with his partner and co-author Victoria, 47 - who has had her bosom enhanced from a 26D (26D UK) to 26O (26K UK)

Ivan, from Fort Lauderdale, wrote the book on the suggestion of a friend after dating three successive women who had a breast augmentation while dating him.

While some may dismiss the Convince Her manual as misogynistic or manipulative, Ivan says men's love of an ample bosom is hard-wired into their DNA.

He said: 'I'm pretty convinced that this is a a very deep, primordial, profound thing for men and I have a feeling that the interest in big breasts began about a million years before Playboy ever appeared on the scene.

'What I love about big breasts is not just the visual, it's also the tactile, how great it feels when you're making love to a woman.

'It's the attention she gets, I have to admit that, and it's the feeling of richness - that's there's an abundance, the feeling that life is good.'

Ivan wrote the book on the suggestion of a friend after dating three successive women who had a breast augmentation while

The tech sector worker says that he has perfected his pitch over the years with Victoria's help - and is happy to admit that his first attempt at trying to convince a partner to boost her bosom failed spectacularly

And far from finding the manual shocking or sexist, co-author Victoria, 47, is a vocal advocate of the techniques it promotes.

She said: 'I think it's wrong for women not to pander to their men. If they feel like their husbands prefer blondes, I think you should be blonde. If you like bigger breasts, why not?

'Why not give in to their fantasies or desires? It's really a fairly easy surgery and not expensive, so why not?'.

The Convince Her Manual has sold 3,500 copies globally - and Ivan claims that only one customer has taken advantage of the money-back guarantee.

'Everybody says it works, I have a lot of testimonials - mostly from husbands and boyfriends saying they followed my ideas and were successful,' he said.

'If her having big breasts is really important to you, do you want to take the chance to ask her about it or not?'.

Ivan has spent $20,000 (£12,740) on breast surgery for his partners, including $11,000 (£7,100) on Victoria alone, pictured, left, as a 19-year-old A cup and, right, as a 26O, says it is only right that he foots the bill for the ops

The tech sector worker says that he has perfected his pitch over the years with Victoria's help - and is happy to admit that his first attempt at trying to convince a partner to boost her bosom failed spectacularly.

'When I bought the subject up with my first wife, I bombed completely,' Ivan said.

'We had one of those conversations - "tell me all your fantasies, I'll do whatever you want, just name it". So I said "Okay, I want you to get bigger breasts". It was a disaster.

'But I realised over time that I hadn't sold the concept properly - that was the genesis of the idea for the manual.'

After the breakdown of his marriage, Ivan resolved to be up-front with future partners about his preference for bigger busts - and quickly found his honesty was rewarded.

Ivan met his current partner Victoria in 2010 - at which point his friend came to stay and suggested he should write a book to share his techniques with the world

Far from sowing discord between partners, both Ivan and Victoria are adamant that the manual has rescued failing relationships

He said: 'With the next serious relationship I was in, I let her know that this is something that I was interested in, and she was caught up in the excitement and said "let's do this".'

Ivan's second wife had already had a breast augmentation but, with his encouragement, she decided to go bigger.

He said: 'By this point, I realised there was a way to wrap it up with excitement, and everyone responds to excitement.'

Ivan divorced again before meeting his current partner Victoria in 2010 - at which point his friend came to stay and suggested he should write a book to share his techniques with the world.

He said: 'At first it was very bare bones, "if she says this, you would say that" and here are the words to use. It took a lot of fine-tuning.

'There's been times when Victoria's said, "that approach doesn't sound right, think more about the timing, think how she's going to feel driving to the surgery."

'What shocked me was when I put it on the internet and it started selling.'

Victoria says her enhancements have strengthened the bond between her and Ivan

Victoria, seen posing in Mexico, added: 'It seemed like a brilliant idea - men got to mould their perfect woman and females got to experience feeling empowered and sexy for their men'

Victoria added: 'It seemed like a brilliant idea - men got to mould their perfect woman and females got to experience feeling empowered and sexy for their men.'

Ivan has spent $20,000 (£12,740) on breast surgery for his partners, including $11,000 (£7,100) on Victoria alone - and says it is only right that he foots the bill for the ops.

He said: 'It's typical that the gentleman pays for dinner and pays for breast augmentations.

'She does the work in carrying around the extra weight, so it seems only reasonable that I would pay for it.'

Ivan says that big breasts make sex 'transcendental' for men - and help women become more popular and advance in their career.

'The money we spent on breast augmentations for Victoria has been repaid in her not getting speeding tickets,' he jokes.

'She gets a reaction, obviously she's gone bigger than most women are willing to go. Husbands stop talking in mid-sentence, wives jab them with their elbows.

'We were travelling in Mexico recently and we heard one of the women shout "oh my God, look at those breasts!"

'We go shopping in Victoria's Secret and there's literally nothing that will fit her, they're at a loss.'

Victoria says she normally times her enhancements to coincide with a special occasion - such as Ivan's birthday.

Ivan explained that when they were travelling in Mexico recently, they heard one of the women shout 'oh my God, look at those breasts!' and then they go shopping in Victoria's Secret, there's 'literally nothing' that will fit his wife

Ivan says that big breasts make sex 'transcendental' for men - and help women become more popular and advance in their career

'Normally we do them on his birthday so it's his present - they're always for him and it's his gift,' she said.

'I think that in a relationship you need to have a slight change once in while. A relationship becomes stale if you stay the same person intellectually or physically.

The Convince Her Manual has sold 3,500 copies globally - and Ivan is proud that only one customer has taken advantage of the money-back guarantee

'As your breasts get bigger, your self esteem as a woman goes up too - you feel sexy and in the game.

'You get to have sex with your eyes open. It's thrilling and it's sexy and that's what you want when you go to a club. They've only got eyes for you - they're not looking at anyone else.

'I don't have any regrets whatsoever, I think it's been good for me.'

Ivan has not had any cosmetic surgery himself - but warns that any men planning to utilise the manual's methods need to be ready for their partner's response.

He said: 'Victoria told me that when her first husband mentioned breast enlargement, she immediately shot back "why don't you get a penile implant."

'I think if a husband brings this up with his wife, he needs to be prepared for that and take it in his stride.'

Despite his obsession with giant breasts, even Ivan recognises that there is a limit to the size a woman should go.

He said: 'There clearly is, especially for someone into physical fitness, but we're certainly having fun getting there. To some people, she's too big already.'

But, inspired by the manual, Victoria has plans to go even bigger - and Ivan is struggling to conceal his joy, likening it to a new birth.

'We've been talking about it for a while and to be honest, I kind of feel like it's the excitement of the arrival of a new baby in the family,' Ivan said.

Victoria added: 'It's always twins though!'

And far from sowing discord between partners, both Ivan and Victoria are adamant that the manual has rescued failing relationships.

Ivan said: 'I received an email from a reader recently who was actually thinking of leaving his wife because he was so frustrated about her being flat chested.

'I can understand how shallow that would seem, but when you're going to be with somebody for 40 or 50 years, should you really resign yourself to a sex life that's not satisfying?'.

Inspired by the manual, Victoria has plans to go even bigger - and Ivan is struggling to conceal his joy, likening it to a new birth

Victoria added: 'I think we've saved marriages with the manual. Sometimes that's all a guy wants. He's happy and he loves you but sometimes a man just has to look.

'I don't think it's sexist at all. It's a couple's decision and it is empowering for a female to feel sexy and become her man's fantasy woman.

'You do it because you're in love with a woman, whether it's your girlfriend or wife, and you like big breasts and sometimes you just don't know how to bring it up.

'How do you say to your wonderful wife that you like bigger breasts? The manual will tell you.'

Victoria says her enhancements have strengthened the bond between her and Ivan - but admits there are downsides to having a huge chest.

She said: 'Our relationship is awesome. It keeps on growing - like my breasts.

'There are challenges in having big breasts though. Sometimes I cannot do certain activities I would like to do, I have to restrict myself from jumping, I have to take care of them.