Why would she hide the fact she has a boyfriend?

Anonymous
I’ve known a girl for five months now, and recently she revealed to me when she was drunk that she has had a boyfriend of eight years. Before this, she told me she was single and told me of people approaching her on Valentine’s day last year. As it was her birthday, I just wanted her to be happy and didn’t ask her why she lied to me about her relationship status. We spend quite a lot of time alone with each other on campus but I haven’t found a way to ask her why she lied to me without making things more awkward than they already are. Should I ask her? If so, how should I ask her? I’m quite hurt by her being dishonest with me and probably can’t stay around her for much longer if things are not resolved. Thing is, we work well together in a mutually beneficial manner in uni and I don’t want to lose that.
Why would she hide the fact she has a boyfriend?
1 Opinion