Kyssen på kryssen (1950)

Lasse Brenner is a serious filmmaker (spoof on Ingmar Bergman) who is forced to direct a lighthearted comedy. The filming takes place in different cities across Europe and North Africa so Brenner and the crew have to sail on a cruse ship. Brenner's wife suspects he has an affair with the lead actress, so she also boards the ship undercover to keep an eye on him.