As one of the most unselfish men that you probably would ever come across, ill be the 1st to tell you that men are very selfish in this department.
I would be more open to another women satisfying my women, but not another man. Yeah its not fair from a womens point of veiw, but that is literally the nature of the business. Men are men, but we are no different from animals. The dominant egotistical selfish trait that exist in a man, is the very thing that make him a man.
I think that when you are single then your every fantasy is free to run wild, but when you are in a committed relationship certain fantasies you gotta keep in check. Me personally, I wouldn’t want to be with a woman if I know that she is fantasizing about sexually being with two man.
For me that is an absolute no-no, as a man who take pride in doing anything sexually to satisfy his mate, I wont be able to roll with that. I would move on in a heartbeat.