Nowadays, dating seems as easy as car sharing: a few clicks, a few algorithms, searched, found. Manfred Hügel exclusively seeks women under 60 kilograms. The architect who presents him with a casual dating agency weighs significantly more. Why does he feel more comfortable with her against his will than ever before? Gerlinde Wagner is retired and tries to ward off her loneliness through established rituals. On a dating portal, she meets Rudi. With him, she rediscovers her own city. But Rudi is almost 30 years younger. "For One Night or for a Lifetime" tells the story of how the choice of love remains unpredictable even in times of singles parties, digital dating platforms, and social freedom.