Named after its architect Gustave Eiffel (1832–1923). The sexual sense is based on a comparison of the steeple shape of the high-fiving arms to the shape of the building.
An iron tower built in 1889 on the Champ de Mars beside the Seine River in Paris; a global icon of France and one of the most recognizable structures in the world.
If the Eiffel Tower were now representing the world's age, the skin of paint on the pinnacle-knob at its summit would represent man's share of that age; and anybody would perceive that that skin was what the tower was built for.
I must say a word about the Eiffel Tower. I do not know what purpose it serves today. But I then heard it greatly disparaged as well as praised. I remember that Tolstoy was the chief among those who disparaged it. He said that the Eiffel Tower was a monument of man's folly, not of his wisdom. Tobacco, he argued, was the worst of all intoxicants, inasmuch as a man addicted to it was tempted to commit crimes which a drunkard never dared to do; liquor made a man mad, but tobacco clouded his intellect and made him build castles in the air. The Eiffel Tower was one of the creations of a man under such influence.
1993 April 11, Jack Schnedler, “Paris in one wild day”, in Chicago Sun-Times:
I'm headed back down the elevator, having suppressed the impulse to buy an Eiffel Tower table lamp or pencil sharpener.
1998 June 10, Jill Lieber, “Having a ball in Paris: France hosts soccer's world best”, in USA Today:
Grandfathers decked out in bright yellow and green soccer jerseys, showing off Eiffel Towers shaved into the back of their heads.
1998 July, Terrence Rogers, “City of vapor”, in American Artist, volume 62, number 672, page 28:
Los Angeles is a city of image and imagination: a vast urban expanse filled with buildings and streets, yet relatively free of famous landmarks. There is neither an Eiffel Tower nor a Times Square, no Big Ben or Golden Gate Bridge to symbolize the complex essence of the city.
[Billy:] I'm not gay, dude. / [Malcolm:] No, you don't seem gay, man. / [Billy:] I would be down for a little Eiffel Tower action, though. / [Karen:] Not, gross! [Billy:] Well, that's not gay. […] [Karen, being hugged by Billy and Malcolm:] Squeeze me, squeeze me. Squeezed between my two men. A little squeezin'. [kisses air] / [Billy:] Eiffel Tower? / [Karen:] Literally no, never.
Eiffel Tower on Wikipedia.Wikipedia 