bitch session

noun Slang.

a discussion in which people complain or gripe, usually about a shared experience: Their first date turned into a four-hour bitch session about their ex-spouses' lawyers.

Origin of bitch session

1940–45; originally military slang, from bitch (in the sense ‘to complain’) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019