One Song a Day Takes Mischief Away(1970)

Overview:

Set in pre-World War II Zagreb, the story is seen through the eyes of 6-year-old Perica Šafranek (played by Tomislav Žganec). A dandy from Zagreb, Mr Fulir (played by Relja Bašić), starts flirting with Perica's mother during a family picnic. At first, Perica's father doesn't notice anything, but wants to marry off Perica's aunt, so he invites the man to their residence. After multiple rendezvous, Perica's father becomes aware of Fulir's attempts to seduce his wife.