You wake up every morning next to your wife. You enjoy your life, but you have this inner feeling you want to explore. You are curious to explore but there was always a barrier. You desire to experience what it is like to be submissive and the little spoon. You desire experiencing what it's like to be pinned down to the bed and have your mouth fucked. You want to feel your hole open for another man's cock and have it reshaped to fit his girth.
The beauty of having your hole owned is that because you are married, no one would ever think you'd allow yourself to become property. It becomes the perfect facade, you get to life your married life with the white picket fence, you are the boss at work, you hang out with your bros and drink a beer, you get to relax on the couch while your hole is stretched before heading back home with a load inside of yourself.
No one knows just how fucked your hole becomes because no one sees it but me.
Edit: Another piece of the picture is that when you're in a sexless marriage or when your physical form is less appreciated as time goes on, you want to feel recognized, feel sexy, feel masculine and strong. Of course your bro has your back. Standing behind you holding your back up while you're being fucked by him.