Getting paid with quads

Just another from the "$25NL files":

UTG limps. With J♥J♣ in the cutoff, I raise to $1. Everyone folds, except UTG who calls, and the flop comes a very promising A♥Q♦J♠. UTG checks. Fully expecting to be check raised, I bet $1.50 into the $2.35 pot. UTG disappoints me (a little) by just calling. On the check raise I'd have reraised of course, taking my chances on the immature feline.

The J♦ comes on the turn giving me quads. UTG checks again. I read him as extremely passive, and I don't expect a river bet if I check. So $2 goes into the $5.35 pot. He duly calls. The river is the K♥. He checks again (dancing with the girl who brought him), and, hoping against hope for a check raise (AK, AT ...) but basically resigned to a certain fold, I bet $5 into the $9.35 pot.

Which he calls again, in effect his fifth call of the hand (counting the initial limp), arguably even his eighth call (including the checks). I did mention that he was extremely passive didn't I?

His hand of course is more or less immaterial, but is in fact: A♣8♠. Well played sir, you're welcome at my table anytime.