I know exactly how that feels. In spite of my wife assuring me that my cock was just the perfect size for her, I knew it was lacking. After being with an old BF of hers from 50+ years earlier, she finally admitted it, "Size does matter."
I can totally relate to my wife's need to be penetrated by a lover with a large cock. Although I'll enthusiastically perform oral sex on her for as long as she wants, whenever she wants, it's no substitute for a deep, thorough fucking. As an insatiable Cocksucker, I love that wonderful "stuffed full of cock" sensation I experience whenever my throat is being filled by someone's thick cock as it's being forced all the way down deep inside my inner being!!
Size definitely does matter!!!!