Worthy of comment, obviously
When I was at uni and sharing a house with three female friends (steady), nocturnal activities with respective boyfriends was inevitable. We were mostly polite and respected each other's privacy by not mentioning it if we heard anything through the thin walls (or listened on purpose).

All except for the girl who lived in the room directly beneath mine, who used to actually document how often we did it, what noises she heard and how "annoying" it was in detail on her Livejournal for everyone to read.

Length? Ask Katie - she probably used to time us.
(claireyfairy There's a smell in here that will outlast religion, Sat 13 Oct 2007, 15:25, Reply)