I'm having a complet meltdown with my Sister's choices? Help?!?

I'm a Christian(and it judges this completly) and in the bible it very clearly states that being gay and is wrong. Complet no-no. I'm with that. I try everyday to be a good Christian. But how can I live in a house when one Sister is and the other supports her? They make jokes and stuff. I can't handle it!!!! They don't have respect for my views, and I try not to talk about that stuff around them. So I'm being the better person but how do I deal with being Christian and two sinners like them? Please help! :'(