Am I wrong for having a massive crush on my sisters boyfriend as her brother?

so me and him are both 15, i lowkey have a crush on him, I stay in my room when he is over because im anxious and shy around him ( i come out sometimes because my d@Mn parants want me to get to know him), I RARLY ever feel attraction to anyone, I feel terrible for liking him, but he is so dayum hot, i feel like if she found out she would hate me, Should i just try to ignore him?
Am I wrong for having a massive crush on my sisters boyfriend as her brother?
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