Sorry that this is not much to go on. I believe this fic I'm searching for is AH (purely because it would make the most sense for it to be!).

Buffy and Spike are neighbours, they live directly next door to each other. They are also friends, and frequently have movie nights. Instead of calling or texting to say "come over" - one bangs on the wall, and if the other wants them to come over, they bang in return.

I have a specific memory of this occurring one time, Spike bangs the wall, and Buffy bangs back purely out of instinct, but didn't mean to do it, as Riley (or some other lame love interest) is in her apartment - this upsets Spike.

Does anyone remember this?

Thanks in advance. I don't know what I'd do without this community! <3