Villain is a 57/16 fish who I thought was very aggro.

I think that I played this one horribly. My idea was to isolate him and let him bluff me. Hence the flop and turn checks. Not quite sure what I was thinking by leading on the river, but considering his wide range, I thought it was for value. When he went all in, I was obviously not happy, time was running out and I called thinking that I beat a flush, a random smaller FH or a bluff. But that's silly since he'd never do that with a flush, and probably not with a smaller FH. Also, his line makes total sense, since he would probably check back the flop with trip Ks and bet the turn.

How would you have played it?