@MarziPanda - Don't forget the turkey baster. I saw a talk show in the 70s or 80s where one sister agreed to be inseminated with her brother in law's sperm so the other sister and her husband could have a baby. They used a turkey baster for conception, totally outside the medical community. I know this was probably rare, but I'm thinking odd ball scenarios like this happened, too. I'm thinking this child would be told of it's parentage because it was a national TV show.
There's a man in my area who fathered 20+ children with about 15 women. One of my friend's mothers had 2 children with him because she didn't want the first one to be alone, so she went back for another one -while he was still married to his first wife. I truly think some women were using him as a free walking sperm donor clinic, it certainly wasn't for any child support, as he was pretty much tapped out by the first 5 or so baby mamas.