<------ pay attention to the red flag!
Egads! What a situation! I'm hearing 2 complaints from you.
1. The secrecy that shrouds his interest in porn, even when (it sounds to me) it is an interest you share and are willing to participate in. My innate paranoia is telling me that something is amiss here. Men do not attempt to hide what they truly feel is wrong, or will at least royally p*ss you off.
2. The "gay porn" thing, for obvious reasons. I'm not even really gonna go into that, other than to say that I think it is a valid concern. Get to the bottom of it, STAT.
So, where does this leave you honey??? Only you can know this. The point I want to get across to you is that if this is bothersome to you, then it is an issue in your relationship. And these issues will flare up often. Being married doesn't make it go away, or make it bother you less. So before you get married, you need to get to the bottom of these issues and either reach an understanding about them, or part ways.
I wish you all the luck in the world! Keep us posted!