I've seen comments here and other places from guys who say they were able to accomodate a very long dick because there is a "second sphincter" that will allow it. I've been sexually active for eons and I've never been with anyone who was able to handle more than 6 or 7 inches, myself included. I've seen videos that show fisting bottoms with tops up to their elbows inside. I've always wondered how that was possible? Is the 2nd sphincter what makes it possible without horrible internal injuries to the bottom?