I don't know if you personally are actually catholic or not, but it is my belief that Christianity seeks to invite everyone into the brotherhood and love of God. Regardless of the stances that the Catholic Church and even the pope take on certain issues, the Church and the pope are both products of man, and therefore, flawed. Who's to say that they know exactly what the will of God is? To decide that is to make yourself equal to Him. In addition, even if God is constantly inspiring all of the Pope's actions and thoughts, it doesn't mean that the pope is properly interpreting and executing this inspiration. In the end, all you can do is try to be the best person you can be, and I believe that is what Christianity is truly calling us to do. God calls to all of us to treat others in a non-biased way that accepts all groups of people irregardless of race, religious stance, or sexual orientation. To discriminate or segregate someone based on their sexual orientation (or whatever it is you are talking about, no offence, i just don't understand it) is to judge someone based on something they are born with, and is tantamount to racism, which also discriminates based on a genetic trait. Your religion teacher may or may not agree with these views, but if she treats you unfairly because of your views, stances, or any other issue, then she is a poor Christian and a bad person in my eyes. At that point, you are perfectly validated in destroying her with logic and/or raising a hubbub. You are entitled to and responsible for expressing your views, and I hope you choose to do so. So hopefully there are a few arguments you could make wrapped up in there. Good luck and God bless.
*I don't generally bring religion into things so don't hold it against me 'kay?