Prior communication is always necessary no matter the circumstances, some men are totally inadequate are meant to be cuckolds and surrender their wife or girlfriend to a more SUPERIOR ALPHA male.
For an inadequate husband, boyfriend no matter the reason, it could be his lack of size or he always ejaculates to quick or has no passion and can't satisfy his woman's desire.
When such a couple is already attached or even married and the male wants his partner to engage in a cuckold fetish, purely for his sexual gratification and not necessarily for hers, it typically does not end well. Most women do not understand why their committed partner would want another man to have sex with her after they have committed themselves to one another.
If there was no prior discussion or agreement regarding their roles and boundaries, he just springs it on her, it's destined to fail. Without the necessary communication the intimacy part of their relationship will break down. Occasionally a wife or girlfriend will go along with this cuckold relationship to please him or herself, because she has an open mind and the actual realistic need to finally be sexually satisfied. When the man has not acknowledged any of his inadequacies nor has she ever expressed to him that she is not fully satisfied and the sole purpose for pursuing because he wants to see her with another man. Unfortunately when there has not been any substantive discussion or communication about each other's role, or why they are actually considering the cuckold lifestyle, it usually spells disaster. Under these circumstances she discovers she harbors resentment towards her mate because he still wants her to respond to him as her man, like he is her primary lover, he wants to be the male in charge when the ALPHA male is not present . He is not willing to give up his role and become a submissive cuckold, now she is no longer able to respond to him as the primary lover, she feels torn between two men, when realistically her husband was an inadequate cuckold to begin with but that was never discussed. More often than not, she takes off with the other man because she needs him for her sexual satisfaction and there was never any confusion as to his role as the man.