[Proofrock]

Meh, I don't really like this spot because none of your options are great.

(1) Reraise. BB and UTG folds most holdings except AA,QQ,AQ,55 and Adxd (and MAYBE JdTd, KdJd,KdTd), and they push most of those. BB probably doesn't have AA/QQ/AQ/AdKd, but these are all well within UTG's range. Since you're in bad shape vs. that range (i think -- I haven't pokerstoved it), you'd have to fold. So by raising you're pretty much just folding out worse hands and getting pushed on by better ones or hands that are coinflips w/you.

Since UTG led the 5-way flop, I imagine his hand is stronger than usual, so re-raising probably isn't great.

On the other hand, you deny UTG proper odds to hit any of his outs on the turn if he's behind.

(2) Call. BB may call, UTG always calls, but now it's a protected pot. You're in about the same situation as you were on the flop, except BB is more likely to be involved as well. If BB or UTG had a draw and didn't hit it on the turn his pot equity goes way down, and also he has very little reason to semibluff a dry sidepot in position.

I'm honestly not sure what the best line on the turn is if you call the flop, though, especially since you're OOP. It depends a lot on UTG's flop leading range and what BB does. I would be most inclined to c/f a diamond or a queen, and either c/f or b/f a blank.

(3) Fold. Folding feels really wrong here, and I think option (1) is better if you think UTG will lead the flop with a wide enough range. If UTG will only lead this flop with a tight range of hands that mostly have you crushed, then I guess folding here is an option but I think it's more the exception than the rule.

FWIW, I'd probably choose (2) > (1) >> (3), but (1) and (2) are pretty close for me. I'm interested in hearing more feedback on this.