Not from a jam session, but on the way back from a gig...We were playing two sets (we found out after finishing the first and decided it was safe to start the alcohol intake...) Our drummer started having a few more than perhaps he should have, so we gave him the "get the set out the way and you can drink all you want" deal...anyway, we do the second set and everything goes okay and, as it's starting to get a little late, we pack up our stuff and start the two hour journey home, myself, my bass player and the drummer in the bassplayer's dad's car, while the other guitarist and singer sod off in another car...
So, everything's going fine. For the first half of the journey, Tom doesn't shut up, tries attacking pringles and can hardly keep his head up...then all goes quiet...We pull over so me and Tom can swap to give him the window, try and get him some fresh air. Soon we're off again...about five minutes later, he decides he's going to be sick, so being the considerate person he is, he sticks his head out the window...however, what he forgot was that we were traveling at 70mph and the laws of physics would suggest that, if you throw up forwards out of a car...it's going to come back in.......The bass player and I spent the next hour with our heads out the other window sharing as much as one seat as we could...
Ah, fun times!