[Wahoo73]

I agree with all others who have already posted. Seat #4 already has too much invested to be pushed off his hand by you raising on 5th street and he most likely has an AK hi diamond flush draw. Also, seat #5 betting-out on 5th street should set off alarms for you as it certainly means that he either has at least trips, a flour-flush with a pair or a four-straight with a pair. Fortunately, his 7s and 8s are near-dead so it is unlikely he already has a full-house and it is unlikely he could make one. Although normally having a four-flush with a pair like you have is a strong draw worthy of a raise but in this case it isn't since your A and your 7s are compromised. So at this point, you are unlikely to make a winning hand other than with a flush, and even it might lose to seat #4's higher flush. IMO raising is defintely EV-. I think you should call and be prepared to drop this in a heartbeat if either opponent appears to improve on 6th. Furthermore, if you don't have the stomach for taking this to the river for at least two more bets, then just fold on 5th.

P.S. Yes Jeff, I also think your raise on 4th was pretty bad, as all it accomplished was to bloat the pot making it more difficult for any of you to get away from your hands on subsequent streets.