She stares at me, even though she has a bf?

Basically theres a girl in my cl that i have a huge crush on, and i think she likes me too. But, she has a bf for (get this !) 1year. How do i know she likes me? We catch each others stares in cl and hold it for a long time, like 6-7 secs, or we look away imiediatly if we catch one a nother. And, well when i look in her eyes i just see it. You cant fake the exact look when you trully like someone. I cant ask her out, she has a bf. Plus, we both know we like each other, so neither is gonna belive we can just go on a friend" date. What should i do?