Regarding your 7 year old's desire to see her father:
Sometimes, it is much more painful, devastating, and harmful to the child to continue to pursue the relationship. If the man is willing to use his own children to hurt you, he's not someone who should be in their life. It may be worth some serious thought about whether it is really in your child's best interest to support her relationship with her father. It takes a lot out of a kid to be constantly disappointed and let down by the person they are supposed to be able to rely on most. My stepbrother and stepsister went through this with their mother. We lived in NY, and their mother got into a relationship with a man who was very controlling. She still saw her children sporadically at that point, but the son stopped wanting to see her because of the boyfriend. Eventually the mother and boyfriend moved to Florida (kids were probably 7 and 8 at that time), where contact became very sporadic. The daughter still wanted to maintain contact, and wanted to visit her mother. Not knowing anything about her living situation, my mother and stepfather (father of my stepsister) flew down with the daughter so they could visit. Her mother never showed up for the visit. I guess my stepsister still maintains some contact with her mother, but my stepbrother has not spoken to her in years. Another sad thing was that the mother had a child by another man (after my stepfather, before the controlling boyfriend). The child and my stepsibs are close, but the child has not seen her mother basically since she moved to Florida 15-20 years ago now. I don't think the mother was trying to harm anyone, but she got caught up in something that led her to abandoning her children. She had left my stepsibs and stepfather when they were only 1 and 2 years old, and was unreliable for years before she moved out of state. My stepsister has a lot of problems now, my stepbrother is doing really well. I feel like a lot of it has to do with their attempts (or lack thereof) to maintain a relationship with their mother. Something to think about.