A 40-year-old man in the UK has revealed he has fathered 42 children with women he doesn't know after advertising sperm donations online.
The man, Tom, told Channel 4 presenters on an episode of Steph's Packed Lunch that he leaves a syringe of sperm with the woman after a cup of tea and a chat in the living room.
He doesn't charge for his donation.
"Most of the time I'll go to their home. We might drink tea in their living room and chat for a good while," the man, Tom, said.
"Then I just go into the bathroom and give them a syringe then head out. Sometimes we'll video chat before we meet or talk on the phone. It's good to build trust."
Tom said he advertised his sperm donations online after reading about shortages at sperm banks.
"In 2011 I read so many news stories about shortages at sperm banks and I thought I'd go ahead and apply. I did qualify at one of the more reputable sperm banks in the UK and donated there."
But now he does it on his own merit without a sperm bank.
He said he's willing to travel all over the country to meet women who want to conceive after he learned that some women would prefer to meet the donor who would be contributing DNA to their child.
"Some people, I find, feel a lot better getting to meet the person and even knowing a number of things, like they could help with siblings in the future," he said.
"If they have a teenager one day who desperately might want to meet their biological father, I've always told them I'd be happy to do that. Those are options they don't get through a sperm bank."
He said there is "a cost issue" when it comes to travelling to donate the sperm.
"I've been out of pocket to travel to people to help them," he told the presenter. "It feels like such a meaningful thing I've been able to do."
Tom said he "will help anyone if I think the child will be loved" and added he will "help maybe another 20 families".
Asked what would happen if his children accidentally met and didn't know they are half siblings, Tom said: "We have a Facebook group that the people I've helped are in. I've also created anonymous ways for them to be able to check if a person might be a half-sibling, using encryption."