I've been rewriting a story that I started before joining Lush. It's about a brother and sister, and their respective girlfriends, who rent a cabin in the woods to celebrate graduating from college.
For around a quarter of the story, I introduce my characters and the plans for the cabin weekend and getting situated at the cabin.
For around half of the story, a strip poker game between the brother and sister and their girlfriends takes place. They have beers, lose/win rounds and clothes (until they end up in underwear), and joke around while commenting on each other's bodies and underwear.
The last quarter of the story sees them joking around and commenting on what happened during the game, before retiring to their respective bedrooms. The story ends with the brother and his girlfriend having sex and climaxing, followed shortly after by the sister and her girlfriend having sex and climaxing.
Would this story be categorized as group sex? I ask, because there are elements of other categorizes. But, I think the main one is group sex