Maybe I'm thinking too much

She is definitely a sweet girl whom I met recently and nice to hangout with. But it's complicated. She loves her bf and is certainly not single. My principles says that's that I shouldn't continue to do this as thing might get awkward and very complicated between us. Interaction between us is sweet but I felt empty when these interaction happens but You are very very sweet when we went out yesterday. I do like her as a friend but I'm afraid that things will get complicated between us. So definitely I'd ask her out again and talk with her. Rather to be honest than lying. I know she might stop hanging out with me but somehow I still need to protect myself from being hurt again as in relationship like this always get me crush and burn. I can't let myself fall again I sounds selfish but I have to do this in order to protect my heart and my feelings. If things are meant to be I will assure you I can be a promising guy not the exactly Perfect boyfriend you have in mind but you be protected. If you are reading this, I hope you understand my situation.