The 2 girls want his last name but I don't think my ex will allow another change so I was thinking about leaving them with my maiden name and adding my DH's last name with a hyphen to the end of mine. My DH was going to do something similar add my maiden name with a hyphen before his last name so we would match. Then we would give the new babies we had together just his last name. The one major problem with this is that he has a very ethnic first and last name and our last names are long and don't really sound nice together . Otherwise I like the way our blending of names respect all the children.
My kids- stay with my maiden name
Me- maiden+his (hyphenated)
His- maiden+his (hyphenated)
New kids- his
My other thought is that I speak with my husband to be and see if he would take my last name so that everyone will have the same last name. I really love this solution except the way that my last name sounds with my Husband to be's first name since its so unique of a name. Also I think he is very traditional and is having trouble mentally about giving up his last name.
I would love to hear everyone's opinion on the choices or any others you might be able to think of