Played a gig with the previous lead singer (note previous) at a local venue. When we picked him up he was already drinking, but said it was only his second can (we later found out it was a few more than that at that point). In the car ride over he was struggling to remember the lyrics to some songs and we had to go over them with him, but he seemed ok. At this point we told him to stop drinking and he agreed he would. We got to the venue and the promoter had left a couple of crates to split between the bands, so we all had a couple except the singer (well, we thought ) and started to soundcheck. Anyway the singer kept on drinking all the way through the night behind our backs. When it came to us playing he was so pissed he could barely stand up and talk or sing... We ended up doing a very short set, as we were getting shouts of "next band". We then basically told him to do one and he was out of the band, at which point he somersaulted over the bar (we still can't work out why) and was hauled out by the bouncers.
Got a call the next morning from his girlfriend. The singer was in hospital after throwing himself in front of car the night before, as he thought we all hated him because we kicked him out of the band.
Pretty bad gig as far as bad gigs go...