A slang term for a homosexual in British culture. It is so termed because instead of 'shopping' at the normal crevice the participant has decided to do their 'shopping' round the other side.
James: Graham Norton does his shopping round the corner!
Chris: You mean he goes to Somerfields? I knew that guy was a fucking weirdo..
James: No I mean he likes to shove his erect penis into the chocolate starfish of other men.
Chris: Oh so he shops at Morrisons then?