SH Set confusion

[Supern]

The villain didn't play any hand this aggressive before or after this hand. He seemed like a solid [img]/images/graemlins/wink.gif[/img] loose aggressive player. He haven't seen me getting to much out of line.

Prima No-Limit Hold'em, $0.10 BB (4 handed at a full ring table)

Hero ($75)
UTG ($30)

Preflop: Hero is BTN with 9[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/club.gif[/img]
UTG calls, Hero raises to $0.4, 2 folds, UTG calls.

Flop: ($0.95) 9[img]/images/graemlins/spade.gif[/img], 8[img]/images/graemlins/heart.gif[/img], 2[img]/images/graemlins/club.gif[/img] (2 players)
UTG bets $0.7, Hero calls.

Great I flop a set! A slowplay might just do the trick (only a possible straight draw)

Turn: ($2.35) 5[img]/images/graemlins/spade.gif[/img] (2 players)
UTG bets $1.4, Hero raises to $3.5, UTG raises to $5.6, Hero calls.

Ok time to punish him a little with a raise (a bit on the small side). What, he repops me out of position? Overpair, TP, set, two pair or the awful 76? I call and re-evaluate the river.

River: ($13.55) K[img]/images/graemlins/heart.gif[/img] (2 players)
UTG bets $12.1, Hero ?

He 3-bets me OOP on the turn and make a PSB (very uncommon at these tables).

Most probable hands now: KK (not likely since limp-call), 88 set (prob raise preflop), 33 set (likely), 76s straight (likely) or 98 two pair (not so likely since I have 99). Can be a monsterbluff as well but I think thats highly unlikely. I don't think it's very likely he has QQ-TT or a second pair.

I think he has either 33 or 76. Of course I didn't have the time to analyze this much at the table. [img]/images/graemlins/ooo.gif[/img]

Easy call?