The XXXorcist (2006)

In The XXXorcist, after all other exorcism methods fail, Father Merkin has no other option but to screw the hell (and the devil) out of a possessed woman, Regan Teresa MacFeel. Her Mother, Mrs. MacFeel looks on helplessly until she succumbs to the evil and becomes possessed as well. Father Merkin is forced to fight for his life...with his genitals.