[BarryLyndon]

I highly doubt that villain is playing air on this board and the only way he can turn two pair or TP into a bluff is if he knew what you were holding. Thus, he would check river for showdown value. Thus, he has you beat.

Also, this line is kinduv funky, but more likely than not, he's just hoping that you made your flush as well and is trying to maximize value. Also, since you checked on the river on this board, he knows you are insecure about your hand and is trying to confuse you with the bigger bet.

Barry