Sabina represents extreme lightness of being. Early on, faced with the ugliness and kitsch in life, from her father's repressive patriarchal home to the totalitarian art styles pressed at her art school, Sabina declares war on the ugly and unoriginal through her paintings and lifestyle. Sabina's life is described as a series of betrayals: "Betrayal means breaking ranks and going off into the unknown. Sabina knew of nothing more magnificent..." Her pursuit of freedom leads her to complete isolation and freedom in America.
Sabina's love affair with Tomas is based on their mutual lightness. There is no element of the domestic or usual romantic kitsch in their relationship; instead the two share a playful eroticism. However, like Tomas, Sabina is drawn to the intensity of hea vier spirits. Tereza charms Sabina, and she falls in love with Franz, both of whom are heavy characters. Sabina also feels the occasional charm of the kitsch she so detests, admitting she cries at films of prodigal children and homecomings.
Sabina understands that her extreme choices might leave her irrelevant and alone. This knowledge makes Sabina uneasy; in America, she wonders whether she has anything left to betray. She will also never know what could have happened had she not betrayed so many people over the years; the unbearable lightness of being is that each decision is faced once and only one possible outcome tried. Tomas chose Tereza and burden, Sabina chose freedom and total lightness; neither can know whether they chose correctly.
Sabina also has special relevance as a permanent and ambivalent exile. Kundera, like Sabina, never returned to his homeland.