Cheating husband left me, should my son have his name?

My husband of 6 years cheated with at least 10 women and then left us while I was pregnant with our 3rd baby. We are currently separated planning to divorce. Our son was born yesterday and my husband is involved with the baby and our older children. I can't decide if our son should have his last name or my maiden name which I'll probably go back to once we are divorced. I hate the idea of my son carrying on his family name when he has been so heartless, but I also don't want to make my son feel different because he has a different last name from his older sisters. Thoughts?