Dear Mr. Dad: My former wife got remarried and had a baby not long after we got divorced. I was happy for her and tried to be as supportive as possible, but her husband isn't making that easy, and the two of them are cutting into my time with my daughter and seem to be trying to cut me out of her life altogether. To start with, he's been having my daughter call him "dad," which infuriates me, and my daughter tells me that he's saying all sorts of bad things about me. Even though my ex and I have joint legal and physical custody, they pulled my daughter out of the school she was in - without getting my permission - and enrolled her somewhere else. They pick her up from school on days when I'm supposed to pick her up, and they've taken trips on weekends when she's supposed to be with me. The stepdad also goes to a lot of my daughter's sporting events. I'd be OK with that except that every time he sees me, he gets in my face and has even threatened to "punch your lights out." For my daughter's sake, I've been trying to remain calm, but I'm not sure how long I can keep that up. What should I do?