Midnight Dolls (1979)

A woman is seen getting ready for a shower - she is completely naked from head to toe. The woman is shown from behind a few times, then from the front briefly with all her nudity in clear view. Two men dressed as women arrive at her house and she answers the door holding a towel to cover the front of her body, but leaving the back of her body fully exposed. The men watch her drop her towel and we and they see her fully nude, front and back.