small pot, snapping off a bluff (10-20 bellagio)

[aggie]

I don't have a stellar read on button. I guess he's on the tighter side of the loose-tight scale but he's definitely willing to mix it up a little. He doesn't seem to like to get bluffed. I also don't think he would check behind this flop with an A. My imge is probably tricky Aggro. I've been picking up a lot of small pots. Effective stacks 4k

I limp in MP with K [img]/images/graemlins/diamond.gif[/img]5 [img]/images/graemlins/diamond.gif[/img](no comments on this please), button limps, both blinds limp

Flop ($80) A [img]/images/graemlins/diamond.gif[/img]6 [img]/images/graemlins/spade.gif[/img]3 [img]/images/graemlins/club.gif[/img]

Everybody checks

Turn ($80) T [img]/images/graemlins/diamond.gif[/img]

Checked to me, i bet $60, button instaraises to $160 and i decide to call

River ($400) 5 [img]/images/graemlins/heart.gif[/img]

Check, button qucikly bets $200, i can't figure out what he could have so i call.

Thoughts?