NL100: AK flop TPTK with suspicious river action

[BigBiceps]

Hero raises AK UTG to $3.5, CO (13/7/3) calls, SB calls.
Pot $11.5.

Flop AT8 offsuited. SB checks, Hero bets $5 (meant to bet 6 but slider got stuck), call, call.

Turn T. checked around. Should bet here?

River 2. I bet $6 (stupid size, should have been $12 for a couple of reasons), CO raises to $35, SB folds. Do I call here? The CO is a winning player, but I have also seen him stack off for a full stack with overcards vs sets before. The hand I worry about the most is TJ, TQ, or T9 or similar, but this could just as easily beat a busted straight draw with JQ.

After typing this post I am already regretting folding, but what do other people think.

[LifeTilt]

I usually fire hard on the turn IF something like this happens. That way, if I get raised I figure they picked up 2 pair or better and I usually fold.

As played, I just think this hand screams "I have a 10!!!" Good fold.

[Johnes Benjamin]

you did play it weak but with sb will to act behind him its not likely he is making a move here, and it certainly isn't another K. I would say fold