Boundaries are tough, but if possible do not turn to your L to set them for you. That is not her job. That said, i can't say I've done the greatest job w/boundaries, but I'm doing better.
If H shows up w/o permission, here is advice that I got:
-Don't be there. Or be on your way out. -Let him in, but make it an uncomfortable situation. For example, have a friend there. Have several friends/party. -Turn the tables. Gush and welcome him. It will confuse him as he is used to being oppositional w/you.
M: 16 years Bomb 4/07 OW 20s long gone Divorced 11/09 I remarried New Guy Cooperative r w/X regarding D