Villain is tight-passive post flop, 30/5 stats, but I have seen him cbet. When he fired on the turn I figured a good one pair hand is most likely. I have a standard tag/slag image.
I don't know about him, but seems like lots of tight players would toss one pair to a turn shove, but I thought if I call and the river is a non-club he calls every time.

What do you think? Relatedly, is the turn a good semi-bluffing spot if I had say A x?

Ultimate Bet
No Limit Holdem Ring game
Blinds: $0.50./$1.
5 players
Converter

Stack sizes:
UTG: $97.70
CO: $63.05
Hero: $98.50
SB: $62.60
BB: $96.15

Pre-flop: (5 players) Hero is Button with 5 7
UTG raises to $3, CO folds, Hero calls, SB folds, BB calls.

Flop: K 4 6 ($9.5, 3 players)
BB checks, UTG bets $7.5, Hero calls, BB folds.

Turn: 3 ($24.5, 2 players)
UTG bets $20, Hero calls???