Thanks guys. I actually pushed the turn since the pot was large, I felt I was probably still ahead and if he was drawing to the nut flush he just paired his ace and might call. Maybe 2/3 pot might have been better with the rest going in on the river. He might have 16-20 outs though. Anyway he folded and CO had a set of 4's so it's a shame I didn't get a sidepot going to recoup that loss. Better hand than I expected from CO though.