Should I break off my relationship because he has a spoiled rotten and disobidence stepdaughter?

her stepmother passed 2 years ago and her stepfather is raising her, he gives her whatever she wants and when she wants...he was talking to me over the phone and she heard him called me BABY and she is 14 years and ran to her room like a child...he told me he has to be patient with her and discreet about what he do....she is talking to a therapy for dealing with her mother death....I love this man and want a futre with him...but I think this 14 steptdaughter IS NOT GOING to accept anyone.....what should I do?