Standard this limit is over my head, but...

I'm having a hard time seeing what he threebets you with pf with a 7 pfr that beats you now. Unless he's in love with suited aces and 3 bet you with Ahxh. I think you're more likely to see two pair or another set, and since it's 3 handed on a scary drawy board, I like 3 betting to try to push sb out, or at least charge them for whatever random draw the're clinging to.