[Rush17]

Raise 5th, see how he and the Q react to it, and reevaluate on 6th. I would think that if the Q doorcard had QQ or better, he would've raised you on 3rd. I think the other player probably hit 2 pair, which you're not far behind to. Plus, if you raise 5th, he's probably going to give you 2 pair and unless he improves on 6th, he'll more than likely check it you, and depending on what you hit, you can always take the option and check behind and hope to improve on the river.