Iirc, there were at least a couple of attempts at adding orgy events to the game, but having more than two LIs on screen at the same time was causing crashes for loads of users, so Oni tried to remove that possibility because he wasn't able to figure out how to prevent the crashes. This was ages ago, around .998-.999. I read a while ago in a change log that he thought he'd figured out what was causing the crashes and thought he'd fixed it and was removing the restriction from the game, but hadn't written anything for scenarios with more than two LIs, so it could still be pretty buggy if someone ended up in that situation somehow. I'm not sure what he changed to prevent/allow more than two LIs on screen at the same time. It has always been pretty common glitch to get more LIs on screen even with the restriction in place, especially in the showers. So, in a sense, accidental orgies have been possible since there were more than two LIs in the game, but intentional orgies have always been a bit elusive, at least in the base game