PL50 KK tough river spot

[chopsticks]

I'm normally playing NL but PL tables had so much action going on and a bunch of stupid players so i decided to take a look. Hero had played only about 10 minutes at this table so no reads on villain. Notice the stack sizes, not too deep but semi. River makes it interesting, whats my line here?

Poker Room skin
Pot Limit Holdem Ring game
Blinds: $0.50/$0.50
10 players
Converter

Stack sizes:
UTG: $63.50
UTG+1: $49.40
UTG+2: $51
MP1: $73.20
MP2: $80.10
MP3: $23.50
CO: $43.80
Button: $54.05
HERO: $91.90
BB: $50

Pre-flop: (10 players) HERO is SB with K[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/heart.gif[/img]
4 folds, MP2 calls, 3 folds, HERO raises to $2.5, BB folds, MP2 calls.

Flop: K[img]/images/graemlins/club.gif[/img] A[img]/images/graemlins/diamond.gif[/img] Q[img]/images/graemlins/club.gif[/img] ($5.5, 2 players)
HERO bets $4.5, MP2 calls.

Turn: 5[img]/images/graemlins/heart.gif[/img] ($14.5, 2 players)
HERO bets $13.5, MP2 calls.

River: 9[img]/images/graemlins/club.gif[/img] ($41.5, 2 players)
HERO?

What's the best line here? Rivercard is an ugly one and villain has about $50 left.

Should I continue firing a (blocker?) bet on the river and fold to villains push or should i check-call depending how much villain bets? It's obvious that he will fire here if i check? Checking here would lose a ton of value from hands like AK, KQ, AQ, QQ but betting and facing a push would be a bad one too.