The Unbearable Lightness of Being presents a forceful and very particular view of sex. In this novel, sex is always about power and never about equality; one person always has control over the other. The women in the novel express their sexuality in a desire to be degraded and sometimes humiliated by the men who love them. Through Tomas, one of the novel's main characters, Kundera takes a look at the different kinds of sexual obsessions that drive womanizing men. He ends up arguing that, for some, promiscuity is a compulsion beyond an individual's control. Tomas himself argues that sex and love are completely different things, and that to be faithful to someone emotionally does not require sexual fidelity.
The political turmoil of Czechoslovakia during the Russian invasion is reflected in the sexual lives of the novel's main characters.
Every sexual relationship in The Unbearable Lightness of Being is based on inequality.