AA multiway deep stacks

just check/fold the river and hope he checks behind his marginal showdown value. i like the discipline to bet/fold getting better than 20% pot odds, but it's already too thin.
now well, BB might be a terrible player with the 3bet-coldcall and/or have a lot of KK/QQ, so you can consider jamming river yourself for value. in any case, the spot is annoying.

You get called twice on the flop, the flush gets in on the turn and you still bet... Are the odds of none of them having a FD that high ? I wouldn't think so. Anyway there isn't much more room for value here as if they don't have the flush it's also scary for them and you're representing so strong.
Just to say I'm check/calling the turn.

And what would you do OTR? Just check/fold?

Probably yes. I don't see much bluffs when villain is floating multiway and betting twice here.
He knows you're supposed to have all the TP and OP in your range, he knows there is a flush onboard and he's still betting... what hand worse calling your multiway flop cbet would he turn into a bluff here ?
If it was UTG I'd say stuffs like T9 but BB has cold called a 3bet OOP so he's representing stronger, mostly broadways and medium-high PP.

I'm not sure if the turn bet is that bad. We could still get calls from some Jx or QQ or something like that. And there could be pair + FD type of hands. But I dislike the sizing. I would go a lot smaller. I would bet the flop smaller too.

But as played, fold river. As a general rule, you can always fold vs a river raise if you don't have close to the nuts.

I just check/call the turn and c/f rivers that deep.

100BB this would be a river shove for me.