u can't just pick a roll!
Every so often my husband asks me to ride him during lovemaking. I had always been slender waisted and flat tummied so this was easy and very stimulating for my husband visually, but my husband loves to eat.
One day I was about to insert his large manhood to ride him. I must have lost my balance (being light-headed from his great foreplay) and his penis head locked under a small tummy roll I had developed from eating with him so much. I fell backwards slightly when I lost my balance and apparently this was excruciatingly painful for my husband's swollen member.
We had often fought about me wearing a bra while doing this because my 38C's bounce a lot and it hurts. Let's just say that from that point on he left my bra on when I was to ride him because he swears that if he hadn't caught my bra at the cleavage that he would have died in the shock of being bent out of joint.