Flop Decision 20-40

[ACPlayer]

Assuming he is an tight player his legitimate hands consistent with the pre-flop raise and post flop check re-raise are sets and overpairs and perhaps AK - specially if he thinks that he can get you to fold an AK which should be your min 3-bet hand.

Now, if he is a creative player, he could be bankshotting off the SB and would be willing to 3 bet the flop with a draw or perhaps even two overcards to greatly increase his chances of winning.

So, it depends on your read -- raise or fold.