It makes absolute sense; it's about the male orgasm and being lost in the ecstacy of it.
Admittedly the first verse renders that a bit odd as it suggests ejaculating in the street but there's a bit of creative licence - the narrator is already anticipating that moment.
The glorious hook of the chorus, one of Banks's best, depicts the magic moment.
Aside from the unimaginative fade-out it's a terrific song. They should've been bold and had a post-orgasmic come-down ending.
I gather it's largely a Banks composition and certainly his lyric, and I had to have it pointed out to me by someone here that he is very prominent in the chorus with his vocal line "Beyond the silver rainbow you won't know..."
No definitely not an album closer. Maybe a side opener or a track 2. It would've been an interesting gig opener if they'd ever bothered to do it live.
Excellent description of something that could have been awkward to describe! Not sure if that was me regarding the verse (probably not), but I can definitely hear his vocal as he is doing what we used to call "seconds" in school, and it's high in the mix, surely the most prominent he's been on a Genesis track. Being around the time of The Fugitive, he was clearly willing to wade in vocally. That said, although I don't have a source to hand, I'm pretty sure Phil tried to get Tony to sing the main vocal on the album, and Mike to sing Just a Job To Do, but they didn't go for it.
Would have made what is already one of the stranger album sides in Genesis' ouevre even more odd!
Would love if they had tried it out live.