[sherbert]

I'd go with your fold anytime. In fact I'd have been tempted to fold to his first raise. That might be weak tight but I'd be happy with it, especially against a probably solid but otherwise unknown opponent. He could well have the straight, if not the set and want to knock out a flush draw. I think calling his initial raise would be weak, rather than reraising but less costly - however you need to hit your FH on the turn to have any certainty in the hand, so you're not getting the odds. If he was on a flush draw plus gutshot say, I think he's overplayed the hand, but you need more info on the button to place him on a hand, which in this case you can't.