Foisty Fish

A Foisty Fish is a seedy sex trap, when someone lays waiting naked for you to return, but they aren't waiting in a sexy way, quite the opposite.
Slithering and sliming around the bed, in their own filth expecting sex - but the sight of it is an instant turn off.

I walked in to my hotel room last night and there was a foisty fish laying there waiting for me.