[bobhalford]

I personally would just call it because this river bet is so strange. He's seen you bet into two opponents on every street. You obviously have a great hand. He apparently thinks he can do better than that. Perhaps he's afraid you will check it through on the river having been called all the way down. So I would immediately put the guy on a 4 and just call.

Also consider that villain may be afraid that you have already made a full house and decides to bet his trip 4's just in case you have something like AK and might raise the river, allowing 2 bets to go in on the river as opposed to 3 bets on the river (which would happen if he check-raised the river with trip 4's and you 3 bet with AA/KK full house). If he just check-called, he would be losing value when his trip 4's beat AK. So he just bets out, half hoping to get raised so he can win 2 bets instead of one when he is ahead, and even better when the other limper puts in two bets with AQ/AJ.

The only other explanation for this river bet is that villain's read is that he's in a WA/WB situation and that his AQ/AJ beats your QQ/JJ/TT and wants to donk the river and get called by a worse hand. However, this seems a bit farfetched considering the way the hand played out and the presence of the other caller involved in the hand.