Inappropriate is a very subjective term. Generally, the answer is that court's feel, when children are with their parent will exercise his or her best judgement in regard to what is both safe emotionally, and physically for the children. That being said, I've had cases, for example, I was representing a musician and he was dating a porn star. Mom's lawyer came in with many pornographic films to show how inappropriate this woman was to be around her children. The Judge said, "I doubt she's doing porn in the home. She is doing nothing illegal, and I'm not going to find that this woman is inappropriate for your children. I believe the dad will know what's inappropriate for the children and if there is anything going on, he will prevent it from continuing."