you have the flush...so?

[stigmata]

A weak tight player who check-raises the turn definately has you beat at this point.

The only reason to 3-bet the turn is for a free showdown if your hand doesn't improve.

But I seriously doubt that any pro is so weak-tight that they will fail to 4-bet you with a flush. C'mon - this isn't omaha -- even fish don't get scared that a higher flush is out there. I really think the 3-bet just opens you up to getting 4-bet by a better hand.

I would actually think that a set of Jack are a likely holding here, given his playing tendencies and preflop hesitation where he was thinking "what shall I do with this hand against a TAG UTG raise....."

If there's no possibility that he'll cap then I think it's a clear 3-bet since he could easily have a J with the Ks or Qs, or other, lesser hands.