As said above, run. Run far, run fast, run like Mexican water through a first time tourist. Your priority has to be your daughter and your own sanity. Your gf may be a fine lady, but until she agrees her ex is a horrible person and puts her foot down, her life, and anyone she touches, is going to be hell. You need to have a diary of this idiot breaking the rules in their custody fight, and have it documented by the police, social workers, whoever. Does he any drug convictions? He should not have any custody if he is using illegal drugs and can't get his kids to school. Kids need discipline, and they're going to be in juvi by the time they're 14 with only a partial parent (no offense to your gf, as she barely has them, they have 1 parent half the time, that's 0.5, and kids should have 2, plus others that care about them). Half the kids in my son's gifted/talented class are "nutty" (I often say eccentric), just like you described, and are often the kid with behavioral issues, as they are bored, different, and so on. Your gf's son might fit in perfectly if he'd actually get to school and learn how to behave, but he's never going to learn that in a house with a druggie parent half the time. I'd file a police report as to the possible sexual abuse and get a full check-up, physical and psych, ASAP.