I Don't Care If Your Gay Or Straight Or Bi

As most of you know, I don't care if you're Gay, Straight or Bi, but my parents do. So my mom and my sister and I were in the living room talking yesterday about random stuff. All of sudden one of them brings up my cousin on my dad's side and how she's into girls. She was bisexual, but I think she's a full blown lesbian now. Long story short I always knew they don't condone the fact that she's into the same sex, I swear to you that I went off on them. In a polite way though. My mom is not a bad person, but we disagree on a lot of things especially sexuality. I told her that nobody judges her or others for being straight, so why is it a problem when someone is attracted to their own kind? People are into what they're into and can't help it. She says that it's sh*t and how it's in the bible that it's a sin to be that way. I went on to say That's it's also in the bible to treat others the way that you want to be treated and to also not judge others. In my head the whole time I was saying if only you knew that I think I might be into girls.