CO: $53.16
Hero (BTN): $52.59
SB: $52.54
BB: $51.53
UTG: $61.03
MP: $147.17

Pre Flop: ($0.75) Hero is BTN with J Q
3 folds, Hero raises to $1.75, SB calls $1.50, 1 fold

Flop: ($4.00) Q 3 J (2 players)
SB bets $2.00, Hero raises to $8.00, SB raises to $20.00, Hero raises to $50.84 all in, SB calls $30.79 all in

Turn: ($105.58) 5 (2 players - 2 are all in)

River: ($105.58) 6 (2 players - 2 are all in)

I have around 500 hands on SB and he is a 16/12/2.0. He 3 bets 5.9% so JJ and QQ most likely 3 bet preflop. I don't have any specific reads on him other than I haven't seen him get out of line so far.

Villain is repping a very small value range (QJ which I chop with and 33). A semibluff is also possible (T9s or KTs), but he doesn't seem like the type who would play his draws aggressively. Also I do steal from a lot of buttons (over 45%), so there's a chance (alebit small) that he is semi-bluffing or even bluffing as I do have a wide perceived range. The fact that he donked 1/2 pot on the flop threw me off a little bit as well. Can I find a fold here or did I play it right?

Even though this is pretty much always going to be 33, i still get it in. You pretty much have the second nuts, since he "should" raise JJ QQ, and if he didnt you still have blockers to those hands.

agree.

its a sick spot because villain never ever bluffs in this spot, a 16/12 nit has a set like always.

but I couldnt fold the hand.

you block qq-jj, he reps narrow, i dont think i fold tho.

sick hand, can't fold. if he has 33/QQ/JJ = cooler, make a note that he donks with a set.