Lyric discussion by Turbovolver 

Cover art for Brick Shithouse lyrics by Placebo

I think it's darker than that. According to urbandictionary.com, a Brick Shithouse can be an outdoor toilet, and I get the feeling the song is designed to conjure up images of actually being trapped in the lower part of such a toilet. (Yeah, rather disgusting but after "Evil Dildo" I wouldn't put it past them :P)

Basically the singing voice is the old lover, and the voice-overs is the new lover. The new lover has put the old lover "in the ground" (i.e. trapped under the toilet) and that's why he's telling him to "meet the brick shithouse". The only thing this doesn't really explain is the sex references, but this is what I think the song is about.

It seems I'm rather unique in this view :S