First short handed post

[sean c]

Hi everyone. I am brand new to 6-max(just started Monday) and was unsure about this hand. I am one of the few goofballs on these forums that doesn't have poker tracker so i apologize for the manual post.

Party 5/10(6-max 6 handed). CO is a mega fish. Button is a mega LAG who plays poorly post flop. I have been running good and probably have a good table image.

Pre flop: 2 folds, CO open limps, button raises, SB folds, i call in the BB with K [img]/images/graemlins/heart.gif[/img]T [img]/images/graemlins/heart.gif[/img] and CO calls.

Flop(3 players 6+sb): A [img]/images/graemlins/spade.gif[/img]K [img]/images/graemlins/spade.gif[/img]9 [img]/images/graemlins/spade.gif[/img]
I check, CO checks, button bets, i raise, CO folds and button calls.

Turn(2 players 5bb): A little red card.
I bet and button calls.

River(2 players 7bb): Another little red card.
I check, button bets and i call.

Is this a 3-bet pre flop against a LAG? Okay so i chickened out on the river i really wanted to show this hand down but didn't want two bets going in on the river and the LAG pretty much auto bet when checked to so i check/called. Should i have bet/called or bet/folded here? How about the flop check/raise good or no?