Guy's Behavior

Does anybody else find this strange or am I just being paranoid?

My boyfriend has a cousin who he talks to on the phone via text message all day long and then they talk on the telephone every single day. She leaves notes for him on his fridge and he keeps them on there. When I 1st seen them I got mad because they say,"I love you" and it had me wondering who was writing that on his fridge. One time I wrote "I love you" and put it on his fridge next to his cousin's notes and he took my "I love you" down but left both of hers up. There was a teddy bear with a heart on it that said,"I love you" on his coffee table. He said that it came from his cousin. Sometimes when he and I go out he'll say that he has to take a picture of something and send it to his cousin (for example, we went to a park that had a water fountain and he took a picture of it and sent it to her). I found a women's jacket and hair clips that weren't mine, along with a pair of women's panties. I asked them whose they were. He said that they were his cousin's because she had stayed the night at his place. He said that she had slept in his room while he slept on the couch. Why wouldn't she have noticed that she had forgotten her panties? I'm pretty sure if I stayed the night anywhere, even at a family member's house and in their bedroom, I'd be more careful not to leave such a personal item of clothing behind. I think that's strange. I mean, I love my cousins but I don't talk to them every day, leave "I love you" notes on their fridge, or "I love you" teddy bears, and I certainly do not leave panties at their place. Does anybody else find his relationship with his cousin weird?
Does anybody else find this strange or am I just being paranoid?
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