So...Matthew announces over dinner he can now have lots of erections. V raises an eyebrow and points out that Mary is a willing home for said erections.
Or....Mary marries Richard the bastard and one night he forces himself on Mary and Carson hits him over the head with O'Brien's button box (which Mrs Patmore has sold on the black market as a magical box which divulges secrets).
Edith and Daisy decide they should be together as they don't have much luck with the menfolk...and out comes the shoehorn....
I need to get out more 