It's one of the harder realizations to come to terms with as a cuckold. Every cuck wants to see his wife take the big cock she deserves and get all the pleasure she desires, but for me at least, it can be hard not to feel little pangs of jealousy when she gets into the realm of doing things with him she's never been motivated to do with me, her loving husband of many years.
She said something profound once that really stuck with me and helped me get back to the right mindset regarding the change we were witnessing in her behavior. She asked me:
"Is he really taking something from you that you ever had in the first place? Or is he showing us both a side of me we never would have gotten to see without his help?"
I sent her bull a thank you note that night, and she and I cuddled intimately until we both fell asleep, celebrating the results of the journey we were daring to take together.