He is a father and nobody knows

It's not your place to tell anybody. Looks like they both agreed on not wanting anybody to know that he is the father. That said, those things have a way to come out eventually, and more often than not it can be highly embarrassing at that point. My BIL has three kids. The first was conceived in a friends with benefits relationship. He was there when the child was born and for the first year kind of saw the child when the mother allowed it but also more at the urging of my MIL. The mother of the child wanted a real relationship with my BIL. When she realized that wasn't going to happen she moved out of state. We didn't hear from her for a very long time. My BIL was glad to see this 'burden' go. Anyhow, apparently while this girl was pregnant with his first child he also conceived a child with another friends with benefits partner. Those two kids are only five months apart. Unlike the other mother, this mother was all too happy to share the child. Although my BIL kept this child a secret until it was half a year old. Then my in-laws found out about it and the child regularly spent time with my MIL, but only saw my BIL when he happened to be there. Then my BIL entered the military. This is when the second mother seized the opportunity to look for health care benefits. She didn't want support, just the military health care benefits. The military requested a DNA test be done to proof the child is my BILs, who had told them that the child isn't his... The mother never went through with it which my BIL and in-laws took as proof that the child is indeed not my BILs. Now nobody has contact with that child or talks about him. Something my BIL very much prefers. My BIL found a rather young girlfriend and ended up marrying her without telling her about the two children. When he left the military they moved in with my in-laws for a while. While visiting friends, one of my BIL's friends asked my SIL how the second child is... the story came out. Although upset, she didn't divorce him. I guess she believed the it's not his story. Still, he didn't tell her of the first child. Now the mother of the first child fell on hard times and needed welfare payments. What does the welfare office do? They see, if anybody else can pay like for example child support from the father of the child... Again my BIL states it's not his child. Worked like a charm with the second child, didn't it? Well, DNA test was done, it's his, he has to pay up. I assume he finally confessed to his wife at this point, but we don't know for certain as we live far away from them. I can only assume she would have noticed that they have less money to use than they should. Still she stayed with him. While now officially known that the first child is my BILs, we still don't get to see it. He has no interest. Nobody talks about this child either. Well, my BIL and SIL also had a child. Less than two years after that they are divorced for reasons my husband and I don't know. My SIL moved back to her hometown which is far away from where my inlaws live. They get to see the child for now every so often but it looks like it's just them who have an interest in seeing her not my BIL. They take care of the child when she is supposed to visit her father. My guess is, once she starts school our family won't see much of this child either. And my BIL rather not have the responsibility anyway. As this illustrates, stuff like that comes out eventually even if both parties involved want to keep it a secret. The only person they hurt is the child who has no idea who the father is and/or feels like the father has not interest in him/her. I remember the second child's utter confusion even at the age of four as to who is actual father is. That is IMO the saddest part about the whole situation.

It is a secret that they have together and I guess they want to keep it that way. Who does this child think is the father. Is the mom telling someone else that he is the father? hopefully it doesn't come out and hurt the child or the other father in the end.