I had suspected her infidelity, although accepted it. I came home early one day and saw her through a window. I watched it all. We made eye contact a few times.
After he left, we talked about it and a cuck was born.
My first time was involuntary, I was sick to my stomach seeing it, and oddly aroused. She did not know I was watching, and he fucked the shit out of her. I got that put in my stomach many times after that, which I heard was part of the cuckold angst.