So basically, I have a female best friend. When we first became best friends, we were both in other relationships and so that's why I never thought about me and her as a thing. Skip forward to now and we're both single. I want to ask her out because I basically like her and I'm not sure if she likes me back. Usually I'd ask a girl out either way, but in this case I'm sure that in the case she doesn't like me it'll kill our friendship as well as any potential relationship. She's been my best friend for a year and a half or so now but I only started liking her romanticallly a couple of months ago. What to do?