Der Mustergatte(1980)

Overview:

Friedrich is the clumsy husband from whom his better half vainly expects a wild temper. He wants to make his wife, who is flirting with divorce and the house friend, jealous by feigning an affair. He laboriously organizes an amateurish "in flagrante delicto" with the harmless neighbor, pours alcohol into himself, and stumbles into his first drunken stupor.