A prolific sperm donor who has fathered 22 children has revealed how he spent his Father's Day and why he continues to donate to women.
Professor Ari Nagel spoke exclusively to Yahoo7 about how he feels about his huge brood and how he is expecting his 23rd child.
The Brooklyn math professor has been donating sperm for eight years and first did it to help out a single female friend who wanted to become a mother.
Speaking about his Father's Day, Mr Nagel said: "I got to spend it with five kids but got beautiful messages from many of the others.
"I was taken out for lunch and I took four mom's and two potential new moms and kids to Radio City Music Hall to see The Rockettes."
One of the new parents sent Mr Nagel the following email for Father's Day.
"We are very grateful to you for helping us to expand our family. You have helped to bring so much more joy and love into our lives and we will always honor you for that. We are both sending you our love and best wishes today," it said.
Last week the New York Post ran a report saying Mr Nagel's wife of a decade, Roxanne, had been ‘livid’ after finding out his 23rd child is on the way.
Mr Nagel disputed this telling Yahoo7: "You can't have that many kids without anyone knowing, especially since our kids did hundreds of playdates together with my other children."
Speaking about why he continues to donate his sperm, Mr Nagel said: "It touches my heart how much they appreciate and love me.
"I'm one of 7 and enjoyed being from a large family but never envisioned having as many as I did. When you meet a women or couple wanting a child and how badly they want to start a family it's hard to say no.
"I get a lot of joy from seeing so many happy families that I was able to play a role in creating."
Mr Nagel explained that his oldest son was 12 and 'he plays with many of his younger siblings and I'm proud of the big brother he has become'.
"The other 21 kids are 7 and under and don't fully understand yet but many of them get to spend quality time together."
Since the professor's story went public he said he has had "a lot of requests...(to be a donor) but I'm 40-years-old. I don't see myself doing it at 50."
Mr Nagel shared a snippet of one woman's email request to him asking for a donation.
"One of my life long dream is to become a mother, so I can share the multitude of love I have in my heart with. So am asking you to please don't give up or count me out just yet," it read.
Despite being married, Mr Nagel defended his actions saying the relationship had not been romantic for years and that he and Roxanne sleep in separate beds.
The pair have three children together - a 12-year-old and two daughters aged two and five.
When approached by the Post, Mr Nagel's wife said: “I have nothing to say. What’s done is done.”
Women find out about the professor's services via a range of networks including Craigslist, word of mouth or Known Donor Registry, a free website connecting couples to donors who do not mind being public.
What makes him different to other sperm donors is that he offers up his sperm for free.
Women can pay anything from $300 to $4000 to sperm banks.
The Post reported that Mr Nagel sometimes uses mall toilets to donate his sperm because women often want to meet in public places.
He has also had intercourse with the women.
"They (the women) choose the methodology and some just feel more comfortable the old fashion way.
"Some had to use a fertility clinic and sometimes I just use a cup. One child was conceived through the mail so I never met the mom or the child.
"One daughter was conceived at home but the mom inserted the sperm directly into the cervix, of her partner much like they would have done at a fertility clinic," he explained.
So far Mr Nagel has had 22 children with 18 different women. The first five mothers reportedly sued him for child support successfully.
"I don't know what's more surprising: that five sued or 17 didn't," Nagel said.
"They were all well aware there was no financial obligation on my part,” he told the Post.
Mr Nagel has children in New York, New Jersey, Massachusetts, Florida, Illinois, Virginia, Connecticut and Israel.
He sees some of them once a week, once a year and has never met some of his offspring.
Mr Nagel told the Post he had no regrets, despite half his paycheck going towards his growing brood.
“Financially, it’s bankrupted me, but I’m still very happy with the way things turned out,” he says.
“I got 22 million in the bank — in my kids,” he added.
Despite having enough children for two soccer teams Nagel says he is still in talks with more women to have more children.