Is my boyfriend using me?

my bf and I have been going out for 4 months and I like him a lot. I have pretty big (above a C-cup) (i asked a ques. about them b4). My friends say that my bf is horny, that he's only dating me for how my body is built. I admit sometimes he seems more interested in my than me brain but he is still sweet. The goods things about him are he's kind, sweet, and he remembers important things. The bad things are he is really into my bra size. When he holds my waist I can feel his hand a little higher than my stomach. Sometimes his hand goes up farther(to under my s). when he looks at me his eyes linger on my chest. I'm afraid my are the only reason he is dating me. do you think it's true?