Quote Originally Posted by Irisheyes
Quote Originally Posted by k8s
Chances are QQ-AA will re-raise preflop. A set is always possible so try to figure out whether they have it by raising them when they bet, then if they come over top of you, you're probably beat.
Would a set not just smooth call your raise?
Possibly. That's why you should be suspicious whenever the person doesn't fold.

The difficulty here is that this line of betting from an opponent is identical to that of a semi-bluff. This means that on the subsequent betting round you have to choose between betting huge to protect the pot against a draw and risk losing a big pot to a set, or hedge against losing a lot to a set while potentially giving a discounted card to a drawing hand.