I originally posted part of this to the holdthemoan subreddit, and then learned of this sub, and decided to share.
When I was 16 my mother lived across the hall from a couple of gals that were roommates. One was in her 60s (Bonnie), the other in her early 30s. I go over there one day to get something, and find the younger one is putting up stringers and stuff for Bonnie's birthday, while Bonnie is knocked out drunk on the couch. She asks me for help with decorating, since it needs to be finished before Bonnie wakes back up.
These thoughts of the occasions when she's been flirtatious with me flash through my head. I was mostly sure that I could get her; if I could ever get her alone. But that was impossible, since my mother was smart enough to not let me be there alone with her, and Bonnie hardly ever left the apartment regardless. There I was, in a situation where we were finally "alone" enough to get away with stuff, but not so alone that my mother would come busting shit up. It was the perfect scenario. The best of both worlds.