What do I do when my best friend's crush likes me and not her?

So, as it turns out my best friend's crush now may like me. I don't necessarily like him back, though I have definitely considered him as a future potential boyfriend. My problem is my friend (lets call her Brea) always gets jealous whenever I talk to him, even though I'm not flirting or leading him on in any way. Now it's starting to hurt me and Brea's friendship. She doesn't mean to get angry at me but it happens. Also, I can't completely cut this boy out of my life because he is also a really good friend and I can't stand hurting his feelings as well. What should I do?