There's no way this is doomed yaoi, since the whole plot with the kid is to get the gangs to stop fighting - my guess is they either work together and form a super gang, or the two of them leave to live with their kid.
My fear used to be this organization taking the kid at some point and the two of them fighting together against those mf to keep their family but ending with only them (since the child is "not real"!)
There's no way this is doomed yaoi, since the whole plot with the kid is to get the gangs to stop fighting - my guess is they either work together and form a super gang, or the two of them leave to live with their kid.