Does anyone know where to find a really good refutation of gay marriage on the level of natural reason such as a video clip of Father Corapi or something. I could go down the religious route with this person I am debating with but they are completely anti-religion. So now I am looking for a really good resource just from the point of view of basic common sense like the parts dont fit and how the heck could gay marriage further the human race. Thanks in advance!

My first suggestion would be the Courage website. It is the official Catholic ministry to those with same sex attraction. Here's the LINK. I wouldn't be surprised if you could find something on the EWTN website as well.

i linked a really neat article in this thread that might be of use.

Catholic Answers has an article on this.

http://www.catholic.com/thisrock/2008/0802fea2.asp