perhaps they're not really having sex?
one more thing about my rabbit neighbors (actually i don't hear them all that often i mean my last neighborsex post was like what two months ago?) is that i could hear the dude saying "OH YEAH BABY OH YEAH" and so on and so forth and i'm just thinking "dang i didn't know that real people having real sex actually said stuff like that!" it just seems really contrived to me.
or perhaps they were watching porn? that wouldn't account for the sound of something hitting the wall, though. twice.
or making porn! (makes more sense!)