One time I passed my Momma in the hallway to our toilet. The hallway was narrow and Momma faced the wall and flattened against it to let me by. Seeing her plump butt there like fruit for the picking, I pressed my groin into it and grinded lewdly, expertly aligning my already hardened cock with her tremendous buttcrease. She said "Hey!" and pushed me away and seemed dumbfounded. I just stared back and said "Yeah, baby" and thrust my crotch toward her. She went to her room and cried. It was never spoken of again betwixt us.