Regarding homosexuality, it appears to be psychological. since homosexuals can be reoriented to be straight and many have been. It can work in the reverse too. Apparently the statistics are quite high for men who join the navy becoming gay because their "sexual orientation," if you want to call it that, changes when they are away from contact with the opposite sex for so long. Because of that, Catholics don't recognize it as true and good sexuality.

Here are a few articles on the subject, for informational purposes.

Disclaimer ;): I'm not trying to force my beliefs on you, just trying to give you something from our perspective. If you are offended by it, I'm fine with you saying that, but please be respectful, I'm not trying to start a hate war here.