Friends with english teachers wife?

okei...so...i've known my english teachers wife since i was like 3.....WAYYYYYY before he even knew her....(shes my brothers x-gf and we were really close) and so....its just kinda weird that im friends with his wife.....has any1 else been in this kind if situation? cuz i wanna call my teacher carman(thats his name) but i hafta call him mr.smith..and its really weird