Should this have been a bet/fold situation?

[sternroolz]

Commerce $20-40. Villian is a loose passive player. He has gotten aggressive a couple times very briefly and in extremely spazzy ways. I at one time in the past thought he was a pretty decent player. I was wrong. He had been playing in the $40-80 and recently started playing more $20-40. I think a few of the $40-80 players are still crying.

I raise A [img]/images/graemlins/club.gif[/img]K [img]/images/graemlins/club.gif[/img] UTG+1. A caller and villian calls in BB. Flop is KJx rainbow. I bet, fold, villian calls. Turn is a brick. I fire again and again villian calls. River is a jack. He checks, I check.

So is check ok here or is this b/f?