In my opinion, there is not a lot you can beat right now so I would slow down. The flush has hit, the two over cards that someone would call a raise with and call a flop with have hit. You can only beat, in my eyes, a straight draw (which he probably wouldnt have called the preflop raise with or pair lower than yours- 99, 10 10. However, if he is aggressive post-flop he most likely would have raised with an all undercard flop. I would check-call the river, because your only subjecting yourself to a raise if he did catch an overcard/flush draw or was slow rolling you with a set.