Jean-Paul Sartre was a notoriously skanky man who managed to secure a woman whose writing talent exceeded his own, namely Simone De Beauvoir. Not only did Sartre keep Simone by his side for the majority of their adult lives, but he also managed to cheat on her repeatedly. How did the dada of existentialism pull the wool over the eyes of a self-described feminist for so long (remember that De Beauvoir authored The Second Sex)? By casting infidelity as a sort of liberation or freedom, of course.
Desiring total freedom for himself, Sartre wrote, "I dreamed above all of asserting this freedom against women". Satre adored his self-sacrificing mother, and his seduction tactics were closer to nostalgia than Casanova courtships. It seems that Sartre did not actually dislike women-- he did not seduce them and leave them due to any hatred of the female sex-- but rather preferred women to men because they were less inclined to argue with him. By agreeing with him and continuously validating his views and preferences, women comforted Sartre, or made him feel "masculine" in the most conquering sense of the term.
Sartre told de Beauvoir there were two kinds of love: "necessary love" and "contingent love". Contingent love was not important, as it was bestowed upon "peripherals", who held his regard on no more than a "two-year lease". On the other hand, the love he had for Simone was of the permanent and necessary sort-- she was a "central", as opposed to a mere "peripheral". She and Sartre could have their peripherals so long as they remained each other's central, necessary loves. By rule, however, both must show "transparency", or what historian Paul Johnson refers to as "just another word for the favorite intellectual game of sexual openness".
Was de Beauvoir redeemed for her beliefs and defenses of Sartre? Was she rewarded for being his lifelong ally? Did making Sartre the "center" of her universe add coherence to her life's story? Alas, hell no. In 1965, Sartre had secretly adopted one of his young mistresses as his daughter. When he died, his little daughter-mistress inherited everything, including his literary property, and presided over the posthumous publication of his manuscripts. So much for a lifetime of growing old together.