$25NL HU Trips 3s

Villain is very passive for HU play. He tends to bet minimum when bluffing and tends to insta-bet pot when he has a large made hand. He has called me down light lately and I have had the best hand every time. Can he really be that bad and raising QT here? I beat every 3 in the book. I discount A3 b/c he has been opening from the button a lot. The only hands he can really have here are AA/QQ/Q3/T3/3x.

Heres the hand:

Hero $40-BB
Villain $30-SB/BTN

Dealt to Hero :Kd: :3h:

SB completes, Hero checks

Flop ($.50): :Ah: :3s: :Ts:

Hero bets $.50, SB calls

Turn ($1.50): :3d:

Hero bets $1.25, SB calls

River ($4.00): :Qh:

Hero bets $2.50, SB raises to $11.50 (insta-bet pot), Hero calls/pushes?

push