<human>: Could you distill the essence of the text into 1-3 sentences?

Some background: I am a High School girl dating a boy that identifies as bisexual. She likes him, but whenever it comes up that he is bi, it turns into a huge blowup. Strangely enough, she has close friends that are gay, and she isn't at all a homophobe. She insists that the only reason she gets worried about us is that "he is not bi, he is gay", and has mentioned a rule that "you don't date bi guys" (about guys dating bisexual girls, she could not be reached for comment). As he has never seriously dated a guy (or even kissed a guy for that matter), I would classify him as bicurious or attracted to both (he has had a few girlfriends that he was somewhat sexually active with). He is a very sweet boyfriend and I have never had any reason to worry about him not being attracted to me. However, she claims because "she's been around the block and talked to bi people, both male and female", and that her authority on the subject trumps mine because I'm not yet legally an adult. She's not forbidding me from seeing him, but it's clear that she's upset for some reason. 

So, Reddit... what do you think?
<bot>: my mom claims that if A is straight and B is gay, then my boyfriend, who is dating and attracted to me, a girl, is not AB or A/B but B, and thus cannot fully love me.