The men who have sex with strangers 'for free' to help them have babies As sperm bank prices soar - women turning directly to online 'free sperm donors' These men offer 'traditional insemination' - sex - to the prospective moms Service is offered for free and is part of a small but growing trend online Kyle Gordy, 23, will travel to see the women or they will go to him Other sperm donors such as 'Joe' estimate to have slept with 100 women Joe says that in his seven-year career he has fathered more than 30 kids His wife and three teenage children have no idea about his double life Watch the full story on ABC News' 20/20 on Friday, November 14, at 10 pm ET By James Nye for MailOnline No strings attached: Kyle Gordy offers his services to women online as a free sperm donor and has sex with women so they can become pregnant instead of using a sperm bank 'Joe' is married, has three teenage children, is a successful internet entrepreneur and when he can jets off around the country to have sex with women in secret as a 'free sperm donor'. Though he is unwilling to reveal his true identity for fear of his wife finding out, Joe describes his home life as 'Clark Kent' and revels in his 'Superman' style alter-ego offering his services to women through 'natural insemination'. Estimating that he has fathered more than 30 children through his seven-year 'career', Joe is part of a small but growing trend online for women to cut through the red-tape and cost of traditional sperm banks to become pregnant. Offering their services on the Internet for free, donors are contacted by women who want to become mothers 'the natural way', believing that having sexual intercourse is the most efficient method to conceive. After meeting online and going through a vetting process, Joe will arrange either to ship his sperm for a more traditional artificial insemination, or will arrange to fly to see the women and donate 'directly' through sex. Talking to ABC News' 20/20, Joe said he has slept with more than 100 women as a free sperm donor, but claims he is discerning. 'I'm not having intercourse with these women when there's no chance of pregnancy,' said Joe to ABC News, without explaining exactly how he would know that. Confirming that his wife and children are clueless about his double life, Joe says that he is fulfilling his own dreams through natural insemination. I have a Clark Kent life. Then, I have the Superman life,' Joe said to ABC News. People might want to have millions of dollars in the bank, and then, you know, some of us might want to have dozens of children out there. Facebook: On his social media page Kyle advertises himself as a sperm donor and to date he has already fathered one child as a 'free donor' As well as helping a woman to have the child she wants, Joe gets to add his progeny to the world. 'I'm unable to have as many children as I want in my relationship, and that would be unreasonable to ask a woman to give birth to 30 children,' said Joe to ABC News. Asked when he will stop, or what his goal is through natural insemination, Joe seemed to aim high. 'The World Health Organization said I can get up to 2,500, but I don't think that will happen in my lifetime. The other donors I know who have a lot [of children] are up there around the 100 range. I'm standing on the shoulders of giants,' said Joe to ABC News. 'I have the satisfaction of knowing that I have another descendant out there,' Joe said. 'It's not the road. It's how we get there, if we actually get there.' Another free sperm donor who did wish to be identified was 23-year-old Kyle Gordy. History: On his profile, Kyle shows prospective mothers what he looked like as a child, outlines his education level, IQ and the occupations of his brothers and father He is currently working towards his master's degree in accounting and like Joe, offers women the chance to get pregnant by having sex with him. 'I don't do any drugs. I don't smoke. I don't drink. I don't drink caffeine. I eat only sperm-friendly food: wheat, brown rice ... fruit and vegetables,' said Gordy to 20/20. During the course of his interview, Kyle was very complimentary about his family tree and genes. 'Right now I'm attending university. Both siblings are engineers. The nuclear engineer is my twin. My grandpa was a scientist,' said Gordy. On his Facebook page which advertises him as a sperm donor, Gordy has posted pictures of himself now and as a child along with his IQ. Gordy told ABC News that he is not just looking to have sex with women, but to genuinely help them to have a child. 'I'm passing on my legacy and giving these people kids,' said Gordy. To date, Gordy has fathered one child and another one of his recipients, 44-year-old Serena, drove two hours to his home to be naturally inseminated. Traditional: A small but growing band of women are eschewing traditional sperm banks to use men who offer their services online Serena, whose identity has been concealed by 20/20 said that she has longed for a child. 'Always, since I was a very young child, and sometimes career and life just gets in the way,' the insurance broker told 20/20. 'Then oops, I'm 38. Oops, I'm 40.' Another important facet of free sperm donors is simply that, no cost. Serena said that she was unable to afford sperm bank fees. Some charge upwards of $1,000 for one vial. She said that after searching the Internet for alternatives, she settled on free sperm donors and natural insemination. 'I felt that there's maybe no other alternative for me. My clock is obviously ticking loud and louder every day,' she said to 20/20.