The Invitation (1973)

After the death of his mother, a middle-aged insurance salesman inherits her small cottage. Selling the cottage, which is attractively located near the center of a big city, makes him a rich man and he buys a large house in the countryside. The salesman then decides to throw a big garden party and invite all his colleagues from the office. Loosened by large amounts of alcohol, the guests gradually shed all their inhibitions and reveal their innermost frustrations.