Retarded turn bet.

PokerStars No-Limit Hold'em, $0.25 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver Cards)

SB ($24.75)
BB ($23.45)
UTG ($25.50)
MP ($24.65)
CO ($101.65)
Hero ($48.15)

Preflop: Hero is Button with , .
2 folds, CO raises to $0.75, Hero raises to $2.75, 2 folds, CO calls $2.

Flop: ($5.85) , , (2 players)
CO bets $2.75, Hero calls $2.75.

Turn: ($11.35) (2 players)
CO checks, Hero bets $7, CO raises to $21, Hero folds.

Final Pot: $25.35

Results in white below:
No showdown. CO wins $25.35.