I have an average sized cock — somewhere between 6.5 and 7 inches in length and average girth, and up until a year ago I was the biggest my wife had ever had. Before that she had always been relatively well sheltered. She didn’t watch porn and was a virgin when I met her. All in all she was just relatively inexperienced when it came to sex.
The first time I saw her with a bigger cock was after a night of drinking games with another couple who we are good friends with, Gabe and Kara. We had more or less expected things to progress sexually so when things got heated between my wife and Gabe it wasn’t a surprise. The part that I hadn’t expected was the role Kara would play in turning me into a cuckold for the first time.
Gabe had a HUGE cock. Kara later told me it was 9 inches and with plenty of girth and that still seems small compared to what I thought I saw that night.