When I went to a Christian private school, I got accused by a straight guy that my iPod had "gay" music on it simply because it had a bunch of girl artists on it.
Then when I started stanning for Kelly in high school (public school), no one had any idea or accused me of being gay when I openly stanned for Kelly. I think it's because she's known for rockier songs like Since U Been Gone, and if people were to ask me why I like her, I would say I love breakup songs, I love a rock sound, and I love a woman's singing voice and hers is exceptional. The last reason is something that they probably interpreted as "straight" because it sounds like I had an attraction to girls. While, what I said was true, I was still gay.
Very few people suspect me of being gay until I come out to them, even with my music taste.