Man has sex with dead mother

A man walked into his mom’s house to find himself alerting the police she was dead when a autopsy was done they found dna fluids and found it was determind to be semin of a young man in his early or mid twentys when dna was ran it turned to be the decesed mothers sons semin when asked he simply replyed I like to have sexual intercourse with dead wemon I dont have a clue why I am sick in the head I know but I cant help it