If she doesn't want to expose you to her friends or family, nor have you around them, she isn't the one for you. Trust me. The last gf I had was the exact same way minus the fake bf part.
Why do you want to be with someone who doesn’t stand up for you and lies about you? Don’t you have more self respect than that? What if you want to get married ffs you gonna wear a mask, how is this gonna give you a future together?
leave her ass!
Sounds like a cover for getting caught talking about her *real* other boyfriend.