I am writing a paper that is saying pre-marital is ok (look below 4 reason).Where can I find GOOD sources?

I am all for chastity. I am living a chaste life and used to give chastity talks my junior and senior year of high school. But my English teacher wants us to take a curve on the topic we have chosen for our argument essays. Since my orginal topic was chastity, my curve is to take the opposing side and be all for premarital . Where might I find some good information to argue that it is ok?