Kostya and Olya are university professors. While on vacation at a sanatorium, Olya becomes infatuated with a more respectable man, Sergei. Kostya, unable to find a better way to regain what he has lost, decides to get close to his daughter Sonya - it is the only way to get close to Olya again and try to talk to her. Sonya is not too interested in Kostya, but the idea of pissing off her father at dinner with his new girlfriend seems very tempting to her: especially after he threw out her boyfriend Max for being "not serious". So husband and wife find themselves under the same roof in different couples.