What it means is obvious. As for the origin, one would assume that the YWCA sells, or used to sell box lunches.
What is the origin of the phrase ‘box lunch at the “Y”’? Did it ever have a non-sexual innuendo usage?
Did the YWCA (or indeed, the YMCA) ever sell box lunches?
It apparently has nothing to do with the YWCA (or YMCA):
It apparently has nothing to do with the YWCA (or YMCA):
Excuse me, on rereading your post, it appears that you know about this meaning of it. I still think that it was purely a made-up term with no real connection to the YWCA or YMCA. It just struck whoever made it up as funny that the term happened to resemble some other terms.
I’ve heard a variant, “eating out at the Y”. The YMCA in my hometown used to have a cafeteria and served inexpensive lunches, so it was a double entendre around there. My father used to eat lunch at the YMCA when he was in high school- meat, two veggies, coffee or milk for 15 cents (1930s). I know the cafeteria was there at least into the 1970s.
Yeah, I got it when I was a kid in the '70s.
Since it is such a well-known joke, how did it get around? Movie? Radio? (Sometimes comedians could slip some things by the censors.) One of those risque records people used to listen to in the '50s and '60s?
While box as slang for the vulva or vagina goes back to Shakespeare, the “box lunch” variant doesn’t appear to show up until the 1960s. Same for “box lunch at the Y.”
Word of mouth most likely. One teen/young adult telling a joke to another.
On the other hand, “box lunch” by itself was a common phrase in the early 20th century. Old high school yearbooks of the era often included advertisements touting “box lunches”, which I presume the students would buy on the way to school. IOW it was a lunch that came in a cardboard box, as opposed to one carried from home in a “lunchbox”.
Box lunch is a generic term used to describe lunches to go sold in a box. It has nothing to do with schools specifically. They usually included a sandwich, piece of fruit or other desert, and something like potato salad. Box lunches are often provided at things like seminars. The term goes way back, at least to the 50s.
I first learned this phrase in the 80’s from the David Allan Coe song, “Fuckin’ in the Butt” which was on a collection of his X-rated songs.
You can listen to it on youtube here:
(spoilered for being very NSFW audio)
http://www.youtube.com/watch?v=tIG6y0jErPgThe pertinent verse begins at about 1:25.
It definitely predates the '80s. (As I said, dad said it in the early-'70s.) Also, the YMCA seemed to be going out of style when I was a kid. It seemed much more relevant in movies from the '50s and earlier. (And the YWCA seemed like an afterthought to the YMCA.)
Oh, I didn’t intend to imply that the song I linked to was the origin of the phrase, or that it originated in the 80’s. Just providing a concrete example of the phrase in pop culture, and one of the ways it has spread. 
As Wendell Wagner pointed out in post #2, the phrase has nothing at all to do with the YM(W)CA (nor box lunches, for that matter).
The ‘Y’ refers to the shape of the body when the legs are spread.
mmm
That link says nothing about the origin of the phrase. But it wouldn’t be a double entendre if it couldn’t refer to eating a prepackaged meal at an athletic club. (And I already knew the definition given in the link.)
Sure it could. Eating at the Y and eating a box lunch were independently used as double entendres before 1965. Just because some wit combined them doesn’t inply that the YMCA/YWCA previously served real box lunches.
I used to go to the YMCA day camp in West Los Angeles, and later the YMCA sleep away camp in the Lake Arrowhead region called ‘Camp Whittle’ throughout the mid and late 1970s during the summer. I was also on the YMCA’s one and only failed ‘Caravan’ camp where they drove us all throughout California, Oregon, and Washington for a summer in an oversize van for several weeks. As to the ‘box lunch’ in question, while bringing your own lunch was the norm during the day camp, there were many locations, like amusement park, where it was not convenient for the kids to bring a sack lunch to haul around all day until lunch because of the activities involved and where there was no mass storage available. On those days, I distinctly remember being told to bring $2 (IIRC) for a ‘box lunch’, which consisted of a sandwich, soda, and potato chips. It did indeed come in a cardboard box, though I can’t confirm that the YMCA actually made these (as opposed to getting them from a local deli/caterer). You did, however, definitely buy them from the YMCA folks. Back in the 70s, it seems to me that having a ‘box’ lunch was somehow a way of implying it was of a higher quality and included the chips and drink. Of course, this is just my guess of the possible origin, not any kind of fact.
Of course it does. That’s like saying the title of the South Park movie, “Bigger, Longer, and Uncut” refers only to the uncensored nature of the movie compared to the television show.
Of course–I’m referring to advertisements from 1900 - 1925, and they probably go back farther still.