A co-ed version of a dude's night or girl's night with your OG crew
Ex 1:
Person A: What are your plans for tonight?
Person B: I'm hanging out with the crew.
Person A: Oh, that sounds like fun. Can I come?
Person B: I would invite you, but it's a crew night.
Ex 2:
Person A: I thought you said you were hanging out with your friends. Why is there a pic of a woman with you guys last night?
Person B: I was with my friends. It was a crew night. We've been friends before we met.