My ex hubby has requested for more days with our daughter. She goes stays over with him one night a week. I am not comfortable with that. Can I say no? What happens if he insists?

Why don't you feel comfortable? If it's her father, I don't see the problem of spending time with her daughter, unless your ex is a macabre person and has bad intentions, if so, you shouldn't allow her to spend time with her daughter. but if he hasn't done anything wrong I don't see why he can't and you don't want that to happen