The telling of Cat People by Molina is one of intriguing romanticism full of excitement and sexual situations that stir up Molina. Valentin sees through the lore of the panther transformation to present an allegorical tale (as he calls it) of sexual repression.
Valentin goes beyond the story to analyze the characters and their behavior and to create their backstories. He offers insight into the sexually repressed architect as he explains his attachment to his mother and his need to care for Irena rather than be her husband. These incidents foreshadow and parallel future situations and discussions between Valentin and Molina and expand on the theme of sexual repression as the backstories of Molina and Valentin are revealed.
Molina is sexually repressed by society because he has the same nurturing quality as the architect and identifies as a woman. Molina takes care of Valentin, nurses him when he is poisoned, and nurtures him with stories and gourmet food to continue the theme of repression as explained by Valentin.
Valentin himself is repressed because of his commitment to the revolution; he denies everything else, including Molina's descriptions of food and women in the telling of Cat People. Nevertheless, Valentin understands the story and finds reasons to interject his comments on the sexual thoughts and behavior of the characters. Their sex lives seem to be his main interest in the story, something he needs to talk about, fantasize about, or be part of.
"Storytelling" is the key word in this question. The theme of sexual repression is not only in Cat People but in Molina's telling and Valentin's comments and analysis, as well as in how much of it is played out as their story unravels.