It's Daisy's birthday and everyone is going out to celebrate.  Marsha sees Tim kissing Sophie and gets upset that he's cheating on Daisy as she doesn't know they aren't really a couple.  At the party she tells Daisy that she saw Tim and Sophie kissing at which point Daisy tells her that she and Tim aren't really a couple and they lied to her to get the flat.  Marsha feels betrayed, especially when all the rest of the people knew the truth as well.  Later, no one can find her to apologize.