My boyfriends housemates girlfriend doesn't like me. I think it's because I've known all of them longer and am more comfortable in their house doing stuff like making tea for them all or dancing and singing about while I help clean up wearing no make-up and my boyfriends tracksuit bottoms. Anyway, the other day me and my boyfriend went out and when we got back I saw that my shelf of stuff in his room had been disturbed and I couldn't find my perfume. She and her boyfriend were the only ones in the house but I didn't have definitive proof so I couldn't confront them. A week later my boyfriend was in his housemates room when he saw it and asked what it was doing there and she said she had "borrowed it" because she hadn't brought any. I hate her and want to get rid of the manipulative cow.