Was he on the draw? Or did he have a K? He thought for ages before he folded.

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP1 ($24.75)
MP2 ($4.20)
CO ($15.60)
Hero ($25)
SB ($24)
BB ($5.55)
UTG ($37.70)
UTG+1 ($10.55)

Preflop: Hero is Button with A, K.
UTG calls $0.25, 1 fold, MP1 calls $0.25, MP2 calls $0.25, 1 fold, Hero raises to $1.5, 2 folds, UTG calls $1.25, MP1 folds, MP2 calls $1.25.

Flop: ($5.10) 6, K, T (3 players)
UTG bets $2, MP2 folds, Hero calls $2.

Turn: ($9.10) 5 (2 players)
UTG bets $4.5, Hero raises to $12, UTG folds.

Final Pot: $25.60