Your opponent shows you 37h?? how does he do that?... I bet the pot. If he chases, he has bad odds. You need to think of these hands as a long term kinda thing. If you play it this way 1000 times and he calls you every time, you make a lot of money with about 67% odds right? Plus you can bet the pot again on the turn if he doesnt hit, then he should really fold, if he doesnt, then you get great odds for a big pot and if he folds, he called a pot sized bet on the flop just to try to make the flush with 1 card.