CO is over aggressive and we're not really afraid of him. He's picked up a couple of big pots recently and has been playing the part of the bully ever since. We have no read on UTG by default his flat call probably means mediocre hand or draw.
PokerStars No-Limit Hold'em, $0.25 BB (7 handed)
Button ($38.90)
Hero ($19.25)
BB ($23.85)
UTG ($8.85)
MP1 ($10)
MP2 ($3.95)
CO ($49.65)
Preflop: Hero is SB with

,

.
UTG calls $0.25,
2 folds, CO calls $0.25, Button calls $0.25, Hero completes, BB checks.
Flop: ($1.25)

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,
(5 players)
Hero bets $0.75, BB folds, UTG calls $0.75,
CO raises to $2.75, Button folds,
Hero raises to $9, UTG calls $7.85 (All-In), CO folds.
Turn: ($21.60)
(2 players, 1 all-in)
River: ($21.60)
(2 players, 1 all-in)
Final Pot: $21.60
Results in white below:
Hero has Th 9h (one pair, nines).
UTG has Jh Kh (one pair, kings).
Outcome: UTG wins $21.20. Hero wins $0.40.