[DanTheCardMan]

Look at it like this:

after the betting on the flop there's ~7 big bets in the pot. If you bet the turn and get check-raised by MP2, if CO raises you can fold knowing he had the str8. If CO calls you can put him on an OESD, possibly with backdoor-flush potential. In addition if CO calls, the pot would grow to 12 big bets, more than correct pot-odds to call a 4-outer. Even if CO folds, or if MP folds and CO is doing the check-raising, you'll still have 10 big bets in the pot and the correct odds to see the river card in hopes of boating up. (knowing your player, would he checkraise with the nuts or with a much more vulnerable hand like Q8?)