not sure on some of the names as i never usually watch it but:
the main character was asked by saint (her girlfriend) to move in with her and she wasnt sure,
her friend sugar had a house warming party at her new flat.
she ended up kissing her friend sugar, which makes her decide she does want to move in with saint after all so went round to tell her.
meanwhile theres a housefire at sugars party the place burns down so she also turns up at saints and asks if she can move in for a bit!
they say yes so all 3 of them end up living together!
Hope this helps!!