You don't say?
Yesterday, I went to lunch with some people in my office, including the two highest-up individuals, both men in their late 50s or 60s. Conversation was the kind you'd expect at a work meal when the only thing many of the people have in common is that they get paychecks from the same organization. I'm not sure how it came up, but at one point, one of the VP-types asked the table if people still used the term "going steady" [as an aside, I totally think that term is underused]. I opined that people my age used the terms "dating" or "seeing someone" now to connote a relationship.

Then two of the women at the table (one of them an avid church-goer) looked at eachother and both threw out "Knocking boots! That's what people say now." I looked at them immediately to see if they were joking, but I couldn't tell if they were or not. The best part is that both of these older, grandfatherly men repeated "knocking boots, knocking boots..." to themselves, mulling it over and trying out the phrase. They never were informed that the term refered specifically to the act of intercourse. God forbid that they use that term sometime in a public setting.