JJ on UTG, 3 way 3bet pot

On the flop I would check to the aggressor and re-evaluete on further action.
If CO bets I would just call and take the same approach on the turn.
If I lead I would make it around 1/3 pot. Now you're sizing is a little bit suspicious. Especially on the turn.
You make at easily 20bb with the intention to shove the river for value.

Cheers,
SDK1987

GG Poker - $0.25 NL FAST (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

BTN: 137.56 BB
SB: 102.2 BB
BB: 179.2 BB
Hero (UTG): 118.04 BB
MP: 120.68 BB
CO: 373.36 BB

SB posts SB 0.4 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.4 BB) Hero has J♠ J♦

Hero raises to 2 BB, fold, CO raises to 7 BB, fold, fold, BB calls 6 BB, Hero calls 5 BB

Flop: (21.4 BB, 3 players) 6♦ 6♣ J♥
BB checks, Hero bets 1.2 BB, CO calls 1.2 BB, BB raises to 13.72 BB, Hero calls 12.52 BB, CO calls 12.52 BB

Turn: (62.56 BB, 3 players) J♣
BB checks, Hero bets 3.2 BB, CO calls 3.2 BB, fold

River: (68.96 BB, 2 players) K♦
Hero bets 30 BB, CO raises to 349.44 BB and is all-in, Hero calls 64.12 BB and is all-in

CO shows 6♠ 6♥ (Four of a Kind, Sixes)
(Pre 19%, Flop 96%, Turn 0%)
Hero shows J♠ J♦ (Four of a Kind, Jacks)
(Pre 81%, Flop 4%, Turn 100%)
Hero wins 252.72 BB

This is at GGP. Do you guys know what this means?