[10NL] KK facing river donk

17 hands on villain and i haven't seen him showdown a hand yet. Is villain's donk on the river here missed JT and fds enough here to find a call? I have shown a lot of strength on a paired board. Does villain's river bet scream monster, which he doesn't want to lose value to a check behind?

I don't have any 9x, 7x hands in his range preflop. A suited JT maybe. Suited big Aces, 99, 77 and KQ+.

PokerStars No-Limit Hold'em, $0.10 BB (8 handed) - PokerStars Converter Tool from http://flopturnriver.com

CO ($10.15)
Hero (Button) ($11.84)
SB ($10)
BB ($12.30)
UTG ($16.32)
UTG+1 ($4.40)
MP1 ($10.10)
MP2 ($15.92)

Preflop: Hero is Button with Khttp://www.flopturnriver.com/pokerfo...ilies/club.gif, Khttp://www.flopturnriver.com/pokerfo...lies/heart.gif
1 fold, UTG+1 calls $0.10, MP1 raises to $0.40, 2 folds, Hero calls $0.40, 1 fold, BB calls $0.30, UTG+1 calls $0.30

Flop: ($1.65) 9http://www.flopturnriver.com/pokerfo...es/diamond.gif, Qhttp://www.flopturnriver.com/pokerfo...lies/spade.gif, Qhttp://www.flopturnriver.com/pokerfo...lies/heart.gif (4 players)
BB checks, UTG+1 checks, MP1 checks, Hero bets $1.05, 2 folds, MP1 calls $1.05

Turn: ($3.75) 7http://www.flopturnriver.com/pokerfo...lies/spade.gif (2 players)
MP1 checks, Hero bets $2.38, MP1 calls $2.38

River: ($8.51) 9http://www.flopturnriver.com/pokerfo...lies/heart.gif (2 players)
MP1 bets $4, Hero?

This is a really tough spot. I think you are beating exactly JT and TT here. It would be really nice to know if your opponent is capable of donking an AJ or AK on the river to try and steal the pot on the end. The donk on the river is either a strong hand that is afraid the board will chill the action for a c/r, or opp is donking to steal the pot because a river c/r bluff is way too expensive. I'm curious to know what he had. I would have a hard time laying that hand down, but the board is not wet enough for your opp to feel like he had to protect his hand on earlier streets.

Why no 3bet pre-flop?

I'd say you're almost always beat here - I don't think many people take this line as a bluff at the micros. It's a value bet because they're worried you're going to check behind.

I don't know.. I feel like I've seen enough dumb stuff here to call for this price. (Ax, JT, KJ, 88, even JJ/TT thinking you will call with A high).

But barring strong reads that PFR is a mega mega nit (and even still you have the second best hand in poker), or a mega whale behind you that you want to keep in, I would 3b pre. Stop getting fancy!