How do I ask her out when she has a boyfriend?
I think you should talk to her, ask her how she feels, and if she actually wants to break up with her boyfriend before you ask her out. Tell her that you like her, and if she returns your feelings then that’s good. If she likes you enough, then she’ll break up with her boyfriend. But I have to recommend, go out with her secretly for a while, maybe a week or so, so it doesn’t seem so sudden and look like she broke up with him for you. And if he gets mad, just explain you like her a lot, and she likes you.