Should I feel upset about this hand?

Make it 275 pre. And yeah this is borderline collusion but he can claim he thought Jack high might win the main.

Yes, I know I should have reraised, but this isn’t a strategy post

It does seem shady but not really anything you can do about it. I’ve seen this before where on the surface you’d think it must be collusion but I’ve also seen very weird bets and mistakes people make in dry side pots because they are dumb or just don’t understand how to play them. It’s also a big risk for him to bet that because while unlikely based on the action there is always the possibility to call and he’s betting that much into a 0 side pot. And like others say he can make up whatever reason to bet if pressed on it. So I’d probably let it go but based on my read of the situation/game I might decide to leave.

It could definitely be collusion, but I've seen this same scenario play out many times where it is clear the guy "bluffing" into the dry side pot clearly just has no idea why he is betting. You checked twice and he might have just bet by impulse realizing there is no way his hand is good. Either way it's irritating because he cost you the pot.

I don't see how this can be collusion.

The short stack went all in pre with KQs (standard), and the other guy calls pre with J10 AFTER the OP called. Then he tried to steal it otr after the OP checked twice.

I don't see anything here except alil bit of paranoia but that's me.

He bluffed off hero on a dry side with a hand that can’t win so his buddy would win the main and you don’t see how it could be collusion?

How did he know hero wasn't calling? He's gonna take a chance with $250 of his own money just to possibly help his friend?

I also see people make big bets into dry side pots all the time, they're not trying to collude they're just not thinking on certain levels in poker.

250 into 450 after hero has shown no interest in any street. Seems like a good bluff if he could win the main with a worse ace high. With Jack high it makes no sense unless he had other financial motivations.

He tried to steal what? He was betting into an empty side pot. The bet would only benefit him if hero folded better and the other guy had gone all in with something worse than Jack high, which also didn't happen to contain a 3,4,5,6,7, 9, or T8. So he just stole the main pot if the other guy had exactly J8, J2, T2 or 82. That's only four hands he beats, three of which are some of the very worst starting hands, and one which is mediocre and doesn't seem very likely for someone to go all in with.

There's not really enough info to assume this though, such as how often does the short stack go all in? If it's often, he could of thought jack high was good and wanted to take that chance to go to SD with him after the OP checked.

The chances this was collusion (again, hoping the OP folds) are a lot less then it being just a bunch of goof balls pressing buttons IMHO.

There is one other hand that makes V a winner and it is one the short stack is likely to go all in with…J10 suited. Yes it is a chop but they chop up op money.

So V is pretty sure he can get op to fold. He pretty much knows he cannot win three way at show down but he has a tiny chance HU. His bet is going to cost him nothing but might win. He is effectively free rolling based on position.

Was it good poker, let you decide but it is one a thinking LAG might make but it is certainly high variance.

Was it collusion? Mayb. More likely V saw a free chance to protect a friend that in V mind did not cost H since shorty is likely winner. Not say V thinking is correct or good. But would this be collusion? Well technically short stack would have to know preflop that V was going to protect him. One person alone cannot collude.

Would not make me happy. In a fair room, maybe V gets a warning but honestly, there are plenty of logical ways to explain what he did. It is almost impossible to prove collusion with one hand. Some folks just are that bad.

It might not be collision but there is no way he thought Jack high might be good against the all in player.
As I just showed, he has the fifth worst hand possible.

Why can't the short-stack be on a total bluff, trying to steal the blinds and the raise? Or maybe he just thought "screw it". Maybe the bettor knows this guy is prone to such things and thought he was good if he could get our hero out of the pot.

He could have been, but all small cards made a pair or better. Did you read my post detailing that?

seen this happen a million times

of all the times i thought it was collusion, 9/10 times i later discovered the dry side pot bluffer was just an idiot

the other 1/10 times when he didn't prove to be an idiot, i was always suspicious but never had the evidence

Why don't you bet the turn?

Other guy probably folds and you have a reasonable chance to be good against all in guy.

At the very least, a turn bet (if called) probably slows down the other guy and he doesn't bluff the river.

This.

Actually more this. Double.

After seeing this hand, my instincts are to think more idiot than collusion.

Plus I do think OP played it bad.

I agree that there are far more idiots than colluders. Still, I would be upset by the hand if it happened to me.

About a month ago in a 5/5 home game a player loses a big pot, he's UTG the next hand and throws his last $25-30 in without looking. 4 callers including yours truly in BB with 65s

Board JTT2 gets checked through, river is another J and I lead for $50. As everyone begins to muck it dawns on me I'm betting into the dry side pot, so I have no choice but to proudly table my hand as if the bet was intentional. All-in player had 54o

Nothing to be upset about with the hand. You needed to bet heavily instead of checking…