This is sort of a poker ethics/general game strategy question as well.

Setup: 1/2 NL at Mohegan. Board on the river is: J987Xr. Three players still in the hand. First to act bets about half the pot. Second to act calls, turns over her cards and says, "I have a straight." She had A-10 or something like that. Third player says, "I haven't acted yet." Second player quickly turns her cards over. Third says, "I call," and turns over Q-10 for the higher straight.

Third then looks at me and says, "I wanted to raise, but I thought that would be cruel."

So: Would it somehow be wrong for him to have raised in this spot knowing that he had the nuts against a player who very likely would have called, and who had already shown her hand?

My initial thought was, "Are you kidding? Shove. Instantly." But I can also see that maybe if third just calls here, he ingratiates himself with the table and can use that to his advantage later in the game.

What would you have done? What do you think?

Raise ABSOLUTELY. Good thing this wasn't a tourney - TD could have given 2 penalties. 1 to "second" for showing the hand before action was complete and 1 to "third" for soft-playing (assuming they are using the WSOP soft-play rule re: betting/raising the nuts if LTA)

I don't change my plans.

If I were going to raise, I raise.

(ie, say first two players showed 6-5 and I had a 10. Since I wasn't going to raise in the first place, I would not raise.)

Most folks play 1/2 for ****s and giggles. Its doubtful he called to "ingratiate" himself... probably just a nice guy having some fun. But you're certainly not wrong for raising this spot every time. I'd probably just call in this particular situation (nice guy syndrome), but at 2/5+, I would raise this every time.

Protect your hand!

Yeah it's her fault for tabling she should have known there were three people in the hand lol. And in some places you have to raise the river with the nuts to avoid collusion.

[x] Have absolute nuts
[x] Last to act
[x] Raise

I'd also say that '2nd' may have exposed in an attempt to ward off a bluff by '3rd'. Do the ethics change if you bluff shove?

It's nice and humane of the guy to call behind, but he couldn't be faulted for raising - the mistake is on her and thus the consequences are her problem.

Raise.
I'm not sure how much without knowing all of the stacks/situation. Probably all in, but maybe less if I think it's somehow more likely to get called by the 1st player as well.

Raise. Unless the first to act player was all in, he might have a 10 and call a raise not putting you on a higher straight. I would always act as I was planning to act without regard to the mistake by player 2. Besides, once they see your hand, they'll understand why you raised.

if QT is the nuts, he should definitely definitely raise. This is what he would have done anyway and her mistake shouldn't cost him money.

It isn't wrong for him to raise. Whether it is +ev to raise is another matter. If I saw that the villains had lots of buy ins, had every intention of staying for hours, and were bad, I'd call. If the villains had one buy in, were leaving in an hour no matter what, and were better than average, I'd raise.