Well, the original meaning of cuckolded was that your significant other, during that time period being your wife had sex with other men.
That could be completely behind your back and without your knowledge, or it could be that you were aware of it to some extent, but just couldn't do anything about it, not man enough, not assertive enough. And as there was not reliable birth control at the time, an implication that you might be raising some other guy's kids.
My two cents worth
But I think a lot of guys experience the cuckolding Early on when a girlfriend in high school or college cheats on them with some stud, where the guy is older or more athletic or has some attributes you don't possess which makes spread legs come easy to him.
Later in life, And with somewhat of a perspective change, You start wanting this situation again, it comes comes with a whole soup of emotions as well as excitement and arousal.