Typically a night in which there was alot of drinking or smoking which resulted in you doing something you regret with someone. Like with an etchasketch toy you would draw something and shake it and make it erase
A fart when one is sleeping that is so loud it wakes either you or your partner and at least one of you has NO idea what the hell that was and think their might be someone or something else in the house with you.
Bob: You look tiered Alan.
Alan: Yeh Mrs woke up last night and insited I check the house for burgalers.
Bob: Find any?
Alan: No I knew it was just a Spook of the Night but I wasn't going to tell her that!
Or.
Lilly and dave both wake up in the middle of the night. Dear what was that??? I'm not sure. Go find out then! *smell rises* OH DAVE! ... Wow was that noise me?
The act in which a group of old female friends go out without their old fart husbands. Old gals' night out usually begins slow with dinner and drinks at a restaurant. The evening picks up when the old gals get soused and end up closing down the local nightclub.
The ladies had an Old gals' night out and went to see the male strippers.