2/4 - tptk facing river c/r

Villain is a 6max tag regular, maybe a little looser pre than most. We've never played hu before and are only playing now because the table broke down and there's a fish sitting out we're hoping will sit back in. We've played maybe 6 hands hu so far, nothing interesting yet. Recent history... a few minutes ago when the table was 6-handed he opened utg, I called otb with AKo and he 3 barreled a K97 rainbow 3 turn 9 river with 65s and I called down for ~75bb.

Full Tilt No-Limit Hold'em, $4.00 BB (2 handed) - Full-Tilt Converter Tool from FlopTurnRiver.com

SB ($479.00)
Hero (Button) ($652.10)

Preflop: Hero is Button with Ahttp://www.flopturnriver.com/phpBB2/...iles/heart.gif Khttp://www.flopturnriver.com/phpBB2/...miles/club.gif
Hero raises to $12.00, SB calls $8.00

Flop: ($24.00) 4http://www.flopturnriver.com/phpBB2/...iles/heart.gif Qhttp://www.flopturnriver.com/phpBB2/...iles/spade.gif 2http://www.flopturnriver.com/phpBB2/...iles/heart.gif (2 players)
SB checks, Hero bets $20.00, SB calls $20.00

Turn: ($64.00) Ahttp://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
SB checks, Hero bets $50.00, SB calls $50.00

River: ($164.00) 5http://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
SB checks, Hero bets $120.00, SB raises to $397.00 (All-In), Hero...

im all for thin value ,but i check this river, though id feel sort of dirty for not betting it when he has worse. As played easy fold.

I actually like b/f. This is probably a fold vs his range I think.

Would a 400 nl reg turn Qx into a bluff here?

everything is good now fold

definitely bet/fold river