1 is masturbation. 2 is sex. 3 is a threesome. 4 is a foursome. 5 is an orgy.

1 is solo. 2 is a couple. 3 - 5 is a few. 5 - 8 is several. 8+ is a group.

A group orgy is at least 8 orgies of 5 people or more, or at least 40 people having sex in groups of 5 or more.

However, if they all merge into one giant orgy, then it’s just an orgy again. Which, is really just group sex anyways.