[Filtered to Sarah]
He's your boyfriend--of course he isn't going to listen to your boyfriend.
The same thing that incurred instant tension in Jareth. I wasn't intimidated by him and I didn't let him control me. It didn't help that I loosened his iron grip on Nathan somewhat. Now that you mention it, I'm not entirely sure he couldn't have burned a hole right through my skull with his mind. Obviously he didn't, and he had plenty of reason and oppourtunity.
I'd advise against giving her anything to sink her claws into--that includes broadcasting displays of devotion to Peter when she's around. Peter may eventually forgive her--you know him, so you'll understand it's entirely possible--and Nathan may be able to handle having her around, but there's no telling if or when she might try something in the future. I don't want you falling victim to that.