Re: some other things to consider

Whether you are single and dating, or living together as a couple or married, you need time to yourself; some of that is reality, some is fantasy.... so whether it is at the golf course, the restaurant, riding in the car, mountain climbing, going to the club, clothing store or whatever...what difference is there? Like you said, you cannot be thinking of your s o all the time...you would go nuts...nobody does this. "Hanging" on each other constantly to keep each other honorable; constantly checking on your partner is not the right way and would lead to problems too..
Personally, if watching p 0 r n actually separates two adults from each other, maybe the original bond was never that strong.
Then, what is really important is the adult AGREEMENT that you have between you both. This should have impact on every thing you do as an adult. So, if you get into a comprimising situation, your "bond" or "trust" is what holds you two together and keeps you straight, and with it, sets your limits. You should be able to be away from each other and know there will be no problems.
Discussing these issues should be done before you commit. If something doesn't jive at this point, that's the time to question the relationship; not after a few years of living together.