Considering Kodama Naoko-sensei usual style this seems almost… wholesome? Idk, there’s definitely that "everyone is f* up" on the characters, but it doesn’t seem to be going in a bad path.
Okay, the good news is that she probably thinks that this is not blood sucking.
The bad news is that it probably woulda been better if she thought it was, compared to what she’s thinking.
Obligatory, omg they are roomates.