I [F] stumbled on a swingers gathering at a bar

So I met one of my long term friends at a bar in the city after work, totally casual and we were just catching up as it had been too long since we caught up. The bar we chose I have never been to before, but was swanky and had a beautiful style to it. Also the place had a great buzz to it and lots of beautiful people where there.

We grabbed some cocktails and caught up on all things girls like to talk about, but after about 40 mins my friend got a call and had to leave as her sister was taken to hospital due to a car accident (she was fine, but taken as a precaution). Anyhow we had just ordered another round of cocktails, so I now I had two cocktails to finish and no company. I started to look around the room and I noticed a group at a table. It looked like 2 couples, however after a while I was a little confused as it seemed like the guys were both feeling up both woman at one point.