[RobA]

I think it really depends on your read on CO. Is he someone that bets draws? He could have AXs very easily. And button could have 67s. If CO has a set you're in a tough place, but is he the type to cap the flop with a set, or would he try to be cute with it? I think he's betting a draw (or A8), and now you're beating him.

Is button playing a strong draw straight forward, or slowplaying a set? Depends on your read on this guy.

I think your winning, so bet.