Is fantasizing about you wife having pleasure with other men wrong ?

All ye maidens hede my warning
Never trust the hearts of men
They will crush you like a sparrow
Leaving you to never mend

No, it is quite common. Actually experiencing it is not wrong either, as long as she consents to doing it. Most women find it hard to understand why we would like that if we truly loved them, but it is impossible for any one person to satisfy all their partner's fantasies and desires, and if we truly love them we want to be fully pleasured. Also it is a turn on for a man to know that he has a very sexy and willing wife who is still going home with him afterwards because he is more than just a sex object to her.

thats up to you. i dont find pleasure in that. but i dont find it wrong if that is other mens fantasy.

No, absolutely not. Why do you think, that it is a bad thing?

My wife was virgin, when we met. I was the first in her life and the only for several years. I knew, that it's a selfish thing, because I had several partners before her and I knew that it's just time when she would have sex with another guy. I have two choice: break up because of this, and let her try to have sex with others, or be a part of it somehow. I choose the second one.

Having concensual sexual experiences is more healthy than most things I’ve read here.

...who"s business is it apart from the fantasizer?

No just makes you a cuck ... do you want to lick the cum of other men out of her pussy? Like a humiliation thing?

Yes.