How ugly a board does a pocket pair have to face anyway?
Lets try put him on a hand:
-suited A,x
-suited K,x
-small pair
The way I read it, his call on the flop indicated one of the above. His raise on the flop suggests he has a four flush; and youir reraise on the turn has confused him, so he thinks maybe you have a better flush so he checks the river.
Do I win a prize?