I was in a swinging relationship for several years and my absolute favorite moments were the times just like this image. My GF and I would set up a little drinks and nosh area, dress sexy, and the other couple would come over.
The girls would always sit next to each other and slowly get close to each other. Some clothes would come off but just enough. The conversation would be sexual, but sort of matter-of-fact. One time I just said 'Sarah has been looking to suck your clit all day' and the other girl replied "well we should let her then' - pulled up her skirt and Sarah went for it.
Those moments were so hot. The girls warming up - the women always lead this part - the guys just hanging out, still largely dressed, drink in hand, watching and knowing we were about to get every piece of each of them for the next few hours. The guys would coordinate a little, sharing what their partner likes (she loves a hard fingering, nipples pinch, or a kiss behind the ear) while the girls were getting their bodies wrapped around each other. And then the guys would tell each other, 'let's do it' and the fucking would begin.
