CO is 14/8/6 over 50 hands and I haven't seen him do anything stupid so far. MP3 is a loose fish.

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG ($31.05)
UTG+1 ($140)
MP1 ($119.75)
MP2 ($97)
MP3 ($59.35)
CO ($120.80)
Hero ($100)
SB ($101.80)
BB ($89)

Preflop: Hero is Button with 8, 9.
4 folds, MP3 raises to $4, CO calls $4, Hero calls $4, 2 folds.

Flop: ($13.50) 9, 8, K (3 players)
MP3 bets $4, CO raises to $15, Hero raises to $35, MP3 folds, CO raises to $116.8, ??

My reraise was small but I didn't want to commit myself in case he has a set. But then again it's a draw heavy flop and he could be pushing a lot of draws here. Call or fold?