Yes, over the years I've had the pleasure of bedding four married women, all while working for the same company for many years. There was always a lengthy prior relationship before it became physical, possibly related to my position, personality or intellect, with maybe a bit of attraction to my level of fitness and athleticism, but none of them had any inkling of my size or sexual appetite. I wouldn't say that I'm that large (7.9 x 6.3), but I was clearly the largest they'd had and we enjoyed a lot of great sex. None of these relationships had anything to do with cuckholding; more to do with satisfying their needs and desires, and likely the excitement of a secret relationship. Three of these relationships went on for 2-10 years, while the fourth was more of a one-time fling, but they also each came back for a "final good-bye" after going our separate ways for one reason or another. Their husbands never learned of their relationship with me, although several of them likely knew something was amiss.