Surely another explanation of this sense of shame (in Gen 3:7) is that “eating the forbidden fruit” was itself symbolic of another act associated with nakedness, namely, sex?

This suggestion has made its way into the vernacular; and the presence of “carnal knowledge” as a Biblical expression seems to clinch the notion. (That is, “knowledge” of “good and evil” is akin to “knowing” a woman.) The case can be strengthed in two ways. First, sex would result in childbirth, which combined with immortality would eventually result in overpopulation, so that death would have to result. Second, they immediately realized they were naked; doing so might well mean they came to realize, after they had sex, the potent sexual significance of their nakedness. There are three problems with this theory, though. One is that if indeed they had relations at that time—if the text meant to say so—then the text would have said so, because the text do say so in the very next chapter (“And Adam knew Eve his wife”; Gen 4:1). Why would a symbol be used in Gen 3 and more literal description in Gen 4? Besides, “be fruitful and multiply” bears such implications, as did the notion that Adam was married to Eve, whose body delighted him and to whom he clove. Second, this and many other texts throughout the Bible that refer to the forbidden fruit give absolutely no indications that the fruit stood for anything else than the “Knowledge of Good and Evil,” i.e., a loss of general moral innocence. Third, if the fruit were a metaphor for sex, then sex, like the fruit, would thereby have been forbidden, but sex was a perfectly natural thing, being the means of “multiplying,” and surely not forbidden. It was hardly forbidden by God to a man and his wife; quite the contrary, in fact. It was only forbidden outside of marriage.