wassup

This girl in my program flirts with me constantly. She will flirt with me every chance she gets and I notice everytime. I think she really likes me and I'm not sure if she know's I like her, but she says she has a boyfriend. It seems like she is uninterested in her boyfriend, but it makes it so much harder for me to ask her out to do something. I want to see if she likes me but I make it so hard for myself to ask her out when the opportunity comes. What should I do?