The woman is lying on her back and the man        kneels between her legs. As she balances herself with her feet and head, he holds her    hips and lifts them high up. She arches her back to align her vagina with his penis. He continues to hold her by the hips as he penetrates her vigorously, watching her reactions. An exciting and provocative position, it allows a deep and vigorous penetration, together with a good view of each partner by the other. The position requires  a good flexibility of the woman's      back.