See, I don't know about that either.
I know that if you have a baby, the child gets YOUR name unless you are married, or the father came and signed the BC. OP-since we have concluded this man is devious, do you think he could have perhaps signed the BC and not told you?
OR which I think is more plausible.....The woman could have named the baby his first/middle and last name but her name would have been tacked on at the end.
Alot of these chicks do that by hyphenating, that's how they get around it. And then they mysteriously try and 'drop the mother's name'.
Ex. John Charles Smith-Thomas (Smith being mom's name) John Charles Smith being dad's name.
I don't know where you live but in GA, you can't put a last name on a child that is not either YOURS or the daddy had to sign the BC.
ETA: I didn't mean to offend anyone who may have a hyphenated name.