Collusion Yes or No?

I sometimes wonder if collusion goes on in live games Online. Was this hand two people playing against me or just over-aggressive play on both of their parts. I was playing $1-2 HORSE and we were in the HE leg. I get dealt A-J in a very loose 7 handed game. A middle position player raises and I call the extra bet as well as 3 other players. The flop comes down 9-4-4 and the middle position player bets so I decide to peal one off as does an under the gun player. Turn looks good to me a Jack so I bet out. The Under the gun player raises and the middle position player re-raises. So it looks like I will be trapped for a lot of bets. I decide to fold my Top two pair with top kicker hand. River goes check, check the under the gun player wins with Q-J off. The other donk had a pair of eights. This hand looks real fishy to me. Really looks like they are playing together on the turn, the second player makes it three bets to go with an under pair on a paired board? What do you all think? Was there collusion involved or just some crazy play. Thanks for reading and good luck at the tables. Tony

P.S. – Please remember to click through on my Google banner, above this post.