This is a photo from "House Hunting." It is the penultimate episode of Being Human.
The roommates realize they aren't the only ones having issues leaving the house on Being Human. "House Hunting" is the 12th episode of the fourth season.

Being Human Season 4 Episode 12 Quotes

What happens next is that we're moving into my apartment. Together.


Sally: Aidan, are you asking me to move in with you?
Aidan: Technically, I think I'm asking you to haunt me.