He kisses his wife goodbye believing they are still deeply in love, never imagining she is cheating inside the same apartment building. Perhaps aroused by her husband's kiss, she cannot wait and has sex with the neighbor right in the entryway. When her husband returns for something he forgot, she stubbornly shows only her upper body through the door. Her face looks flushed—could it be? He regrets not loving her more. With only one door between them, this filthy young wife plays two men at once.