Under the Yum Yum Tree (1963)

Plot:

Under the Yum Yum Tree is a 1963 sex comedy farce that stars Jack Lemmon in the leading role as a sex-crazed landlord. He is joined by Carol Lynley, Paul Lynde, Dean Jones and Edie Adams. This was one of the successful small comedy movies that Lemmon despised making (despite him gaining a Golden Globe nomination). It first ran on Broadway in 1960/1.

In this 1963 sex-farce comedy, Jack Lemmon stars as the playboy landlord Mr. Hogan, a swinging bachelor. Women are mere playthings to him, plus he's a master con man. His bachelor pad is a holy temple of seduction: blood-red walls, African sculptures, a well-stocked cocktail bar, and a switch-operated fireplace. He walks around wearing a scarlet blazer (with matching socks) and a devilish smirk. As the landlord of a Californian apartment block, he only rents rooms to gorgeous single women.
The film picks up as Irene (Edie Adams), a recently divorced tenant, has just concluded an affair with Hogan. She's moving out of her apartment, which is immediately snapped up by her näive niece, Robin (Carol Lynley). Hogan is thrilled at the prospect of yet another beautiful tenant to seduce, but is initially unaware that Robin's short-tempered, eternally frustrated boyfriend David (Dean Jones) will be moving in as well.
The temptation is naturally there, but Hogan does his best to prevent David and Robin from consummating their relationship. Irene, who has only lately come to realise the extent of Hogan's promiscuity, is determined to prevent him from getting his hands on her niece. Irene confronts him at his barber, and Hogan is self-defensive and self-deluded to comic effect.
Of note: The car used by Jack Lemmon in this movie is a 1962 Cougar I Concept.