40/80 Ocean's, I river the "nuts"

[Kirkrrr]

Full game, BB seems bad and fairly unimaginative. UTG is very solid and his UTG open range is like AQs+ with perhaps 57s mixed in 5% of the time.
I'm UTG+1 w. A,Ko and have been running like God and killing the game, playing fairly tight and straightforward.

UTG 3bets, I call, 2 more callers, BB calls.

Flop: 449r

BB checks, UTG checks, I donk it, everyone calls.

Turn: 9

checked around

River:A

BB checks, UTG bets, I call, fold to BB who raises, UTG folds, I let out a heartfelt "Dammit!!" and... ?

Kirk

PS. Since I know it will come up, I 4bet AK in that spot virtually always but chose not to vs that particular player.