[coolhanded]

Based on his flop call, looks to me like UTG is more likely to have flushed than SB. SB's flop play makes me think he's put you on AK/AQ, has a T or a mid-high pp, and is 3-betting to get rid of UTG.

Problem with betting the turn is that if you are raised, you could be way behind to an Ace-high flush but you'll want to call it and see the river with K [img]/images/graemlins/spade.gif[/img] and 4 outs to a boat (6s and Ks). Betting the turn and being called won't tell you a lot.

I'd check and see what the river brings.