Mike Rubino has even moved in with one of them, named Jake, after they developed a strong bond with each other. He calls Jake "the greatest kid in the world" and sees himself as his "full-time" dad, adding: "I couldn't be happier."
In the 1990s, Mike decided to help couples struggling to conceive by being a sperm donor. He took the decision because he and his ex-wife had struggled to have a child of their own. Sperm donors are required to sign contracts not to contact any of their children until they reach the age of 18.
However, Jake's mother, Karen Strassberg, asked him if she could meet him and bring along Jake. He and Jake instantly felt a connection even though Jake was unaware then that he was meeting his dad.
Mike said: "I fell in love with that kid instantly. He was the greatest kid in the world." Jake, now 19, also told his grandmother that he felt he had made a new best friend. He later learned that Mike was his dad. 
They now live together in the same house with Karen. Mike is also in regular contact with his other 18 children, with five more yet to contact him.
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