The Torah frequently used the expression "gilui ervah", "uncovering nakedness", to describe sexual encounters. Literally, this refers only to the removal of clothing, and physical contact is implied rather than stated. One assumes that this is a euphemism, used to ensure modesty when discussing immodest matters.
But there are problems with this understanding. In other places, such as Devarim 28:30, the Torah uses more explicit language. Why could the same language not have been used in the sexual laws, particularly when there is the danger of misunderstand the laws to prohibit stripping as well as actual intercourse?
An alternative suggested itself to me on Shavuot morning while hearing Ruth 4:4. There appears the phrase "gilui ozen", "uncovering an ear". From a concordance I learned that the phrase means to inform or command someone. This usage too departs from the literal meaning of "uncovering". You might assume that "uncovering" an ear means to get someone's attention, to make them receptive to speech which might come in the future. But here it means not only that the ear is exposed, but that words enter it and implant some idea in the listener's mind, causing the listener to act differently in the future.
Perhaps "uncovering" has the same additional connotations - penetration and implantation - when used to describe "nakedness". If so, then "uncovering nakedness" is not a euphemism, but a quite exact reference to sexual intercourse. It becomes clear that only the full sexual act is forbidden. Simply disrobing, while inappropriate, does not incur the death penalty.
This understanding of "uncovering" is perhaps supported by Vayikra 18:10: "Do not uncover the nakedness of your [granddaughters], for they are your nakedness." From this verse it appears there is something wrong with uncovering your own nakedness. People see themselves naked whenever they bathe and the Torah permits bathing. So the phrase "your nakedness" only makes sense, even as a metaphor, if "uncovering" means more than exposure.
More support comes from the fact that the phrase "gilui ervah" is used only regarding women. ("Uncovering your father's nakedness" in Vayikra 18:8 means to uncover your father's wife's nakedness, on the principle that married people "become one flesh", Breishit 2:24.) The only verse to mention a man's nakedness - Vayikra 20:17 - says that his nakedness is seen rather than uncovered. Meanwhile, his incestuous female partner's nakedness is both "seen" and "uncovered". Since the man is not penetrated, it appears that "uncovering" cannot be applied to him.
What is the practical difference between "seeing" and "uncovering"? To uncover something means to necessarily see it, and also implies an action performed by the observer to the observed. It is this active role that the phrases "uncovering ears" and "uncovering nakedness" both allude to.
You will undoubtedly accuse me of having a dirty mind, for basing this post on a comparison between the ear and female genitalia. But it is not me doing the comparison, it is the Hebrew language which used the same metaphor for both. And it is not dirty, in the sense that when I needed a metaphor for ears, genitals came to mind. Rather, when metaphors for both ears and genitals were needed, the same third option came to mind. Having cleared myself of the accusation of crudeness, hopefully you will appreciate the interpretation that I have now uncovered.