Weronika and Łukasz – a would-be bride and groom from the first film – decide to give themselves a second chance and invite their family to the wedding and the reception, which will take place in a seaside town. Among the invited guests, the viewers will recognise well-known characters, including: Wanda and Tadeusz with their dog, Mirelka, and also a divorcee, Małgorzata, accompanied by… her much younger partner, Jan , and her mother. The sea, drinks and nude sunbathers make the family members of the bride and groom more open and ready to shed their masks.

Wanda and Tadeusz host a christening for their granddaughter, tension simmering as they reluctantly invite Małgorzata and her psychotherapist friend Grażyna. Just when the family braces for a fraught gathering, Andrzej returns to Poland, stirring old conflicts and transforming the warm celebration into a battleground where no one is willing to back down.

The In-Laws is a hilarious comedy that revolves around the rollercoaster relationship between a married couple's in-laws during the preparations for their wedding. The clash of personalities, unexpected events, and outrageous situations make for a wild and unforgettable journey.