Being a musician is a hard one for relationships.
You get to do something you really like (play music), are constantly exposed to women, booze, drugs, parties night after night. You are on stage and people (hopefully) are cheering and dancing. That stokes your ego in a way that can't be easily matched
You go home to a demanding wife and screaming kids. Or even a calm (but boring)situation.
Adrenaline rush of the stage vs the subtle joys of family life. Easy to stumble on that one.