In a rare situation as reported here by Aol a Texas woman recently gave birth to twin boys who were born with different fathers. The hospital had said it is extremely unusual and they believe the first time and possibly the last it will occur in Texas. The woman had one of the children with her fiance and one with a guy she had a fling with. After the children looked very different a DNA test was done which discovered what had happened. The fiancee was going to raise them both as his own children.
In Florida there is a Florida statute that says that the child will be a child of the adopting parent and a natural kindred of all of the adopting parents family for inheritance purposes but shall lose all inheritance rights to the biological parent who would no longer be treated as the parent so assuming he were legally adopted and Texas had a similar statute or an inheritance issue in Florida becomes an issue that would be the result.