foursome
noun [ C ] uk/ˈfɔː.səm/ us/ˈfɔːr.səm/ (also four)
（聚在一起玩游戏、吃饭等的）四人组
a group of four people meeting for a social activity, such as playing a game or having a meal
Why don't we invite Caroline and Mark and make up a foursome? 我们干吗不邀请卡罗琳和马克来凑成两对？