marks & spencers, commonly said as m&s. well flip it over and its s&m. used when u r in a public place and r tlking about an s&m dude or dudette and wish for them not to know what u r tlking about.
(wierdo pervert s&m bloke Sherman enters the room)
'hey lindsay, i herd sherman is on the marks & spencers flipside...'
'no way! or maybe...'