The play in this hand looks fine, and I'm just gonna throw an idea out there. If he is always slowplaying a hand that beats yours, would he bet the turn if you had checked? Would he semi-bluff a FD on the turn after sensing weakness or check to try to hit his flush? Checking the turn for information costs you value for when he is drawing, so I think the bet on the flop has to be bigger (assuming he's going to draw less on paired boards). I don't really like betting more on the flop though because it's 4 handed. Meh, Idk. I can't come up with a good plan for this hand. The way you played it seems fine, but dissapointing.