This is a passage from Part II, "Patterns of Bad Faith," from Chapter Two, "Bad Faith," in Jean-Paul Sartre's Being And Nothingness (Editions Gallimard, 1943; English translation, The Philosophical Library, Inc., 1956).
"Take the example of a woman who has consented to go out with a particular man for the first time. She knows very well the intentions which the man who is speaking to her cherishes regarding her. She knows also that it will be necessary sooner or later for her to make a decision. But she does not want to realize the urgency; she concerns herself only with what is respectful and discreet in the attitude of her companion. She does not apprehend this conduct as an attempt to achieve what we call "the first approach"; that is, she does not want to see possibilities of temporal development which his conduct presents. She restricts this behavior to what he is in the present; she does not wish to read in the phrases which he addresses to her anything other than their explicit meaning. If he says to her, "I find you so attractive!" she disarms this phrase of its sexual background; she attaches to the conversation and to the behavior of the speaker, the immediate meanings, which she imagines as objective qualities. The man who is speaking to her appears to her sincere and respectful as the table is round or square, as the wall coloring is blue or gray. The qualities thus attached to the person she is listening to are in this way fixed in a permanence like that of things, which is no other than the projection of the strict present of the qualities into the temporal flux. This is because she does not quite know what she wants. She is profoundly aware of the desire which she inspires, but the desire cruel and naked would humiliate and horrify her. Yet she would find no charm in a respect which would be only respect. In order to satisfy her, there must be a feeling which is addressed wholly to her personality --i.e., to her full freedom--and which would be a recognition of her freedom. But at the same time this feeling must be wholly desire; that is, it must address itself to her body as object. This time then she refuses to apprehend the desire for what it is; she does not even give it a name; she recognizes it only to the extent that it transcends itself toward admiration, esteem, respect and that it is wholly absorbed in the more refined forms which it produces, to the extent of no longer figuring anymore as a sort of warmth and density. But then suppose he takes her hand. This act of her companion risks changing the situation by calling for an immediate decision. To leave the hand there is to consent in herself to flirt, to engage herself. To withdraw it is to break the troubled and unstable harmony which gives the hour its charm. The aim is to postpone the moment of decision as long as possible. We know what happens next; the young woman leaves her hand there, but she does not notice that she is leaving it. She does not notice because it happens by chance that she is at this moment all intellect. She draws her companion up to the most lofty regions of sentimental speculation; she speaks of Life, of her life, she shows herself in her essential aspect--a personality, a consciousness. And during this time the divorce of the body from the soul is accomplished; the hand rests inert between the warm hands of her companion--neither consenting nor resisting--a thing.
We shall say that this woman is in bad faith. But we see immediately that she uses various procedures in order to maintain herself in this bad faith. She has disarmed the actions of her companion by reducing them to being only what they are; that is, to existing in the mode of the in-itself. But she permits herself to enjoy his desire, to the extent that she will apprehend it as not being what it is, will recognize its transcendence. Finally while sensing profoundly the presence of her own body--to the point of being aroused, perhaps--she realizes herself as not being her own body, and she contemplates it as though from above as a passive object to which events can happen but which can neither provoke them nor avoid them because all its possibilities are outside of it."
To counterpoint this passage, you might want to take a look at the famous nude photo of de Beauvoir, taken by Art Shay, Algren's best friend, when de Beauvoir was visiting Algren in Chicago (above). Algren didn't have a bathtub in his apartment (he used the Y, I think), so he asked his friend Shay to find her a place with a tub. It seems de Beauvoir never closed the door when she went to the bathroom for any reason, so when she stepped out of the tub and stood in front of the sink, Shay snapped a few quick shots with his ever-present Leica. According to Shay, de Beauvoir said, "You naughty boy!" but made no attempt to close the door, and didn't tell him not to photograph her. New Yorker writer Adam Gopnik said of the photo, "It was quite a rear." I read somewhere that de Beauvoir was buried still wearing Algren's ring, but maybe that's just a story.