anal fisting
sexual activity involving the penetration of the anus by the whole hand, sometimes a form of masturbation
en-US/ˈeɪnəl ˈfɪstɪŋ/
en-GB/ˈeɪnəl fɪstɪŋ/
sexual activity involving the penetration of the anus by the whole hand, sometimes a form of masturbation