[RobNottsUk]

Depends on how large a bet you're willing to call on the river!

So to answer the question, you'll need to decide whether his 2 pair is going to beat your set, and whether the sooted card putting a flush on board gives you quads.

Then how often it'll be a bluff on the river, with 2 pair should the flush (non-pairing come), and how much that player will lose making a flush on a paired board.

If you could be sure it's a flush, then you'ld be happy with a set if they call a 1/2 pot bet, as you can fold on the river.

With 2 possibilities, you should bet more, especially if you can expect to be called by the flush wrongly.

If your opponent bluffs by Pushing In, and Pushes In with the Nuts, then you have to bet more on the turn to deny implied odds, of folding incorrectly or calling incorrectly on the river.