Step-Daddy had been watching my step-sister and I get it on with each other all afternoon while he jerked off. We had already made out for him, ate each other and other stuff when he told us he wanted us to fuck each other. I laid on the floor, upside down to allow better access to my ass and pussy and my step-sister put on her strap-on and stood over me. When step-daddy said GO, she plunged it into me so deep I gasped! It felt so good that we just couldn't stop till we came and watched as step-daddy came too!!