Uh oh, someone mentioned the b word. But I've not, ever, even those with partners of the opposite sex, encountered a bisexual who is against or not passionate about LGBT rights.
Do you think there's the possibility that they're less invested in it though?
I guess, but thinking they're less invested because they have an opposite sex partner is actually rather silly, and a reason why a lot of gay people don't care for bisexuals in the first place. I'll echo a bit of what Vosem said and hypothesize that, if they don't care, it's not so much because of their sexuality than their own personal choice, I suppose?