Ok so bear with me on this. Oral sex is fairly common in current western culture (elsewhere as well of course) but was it always common? I know there are artistic depictions of it from the past thousand years or so, but were people doing it as much then as they are now? Was Mary Todd Lincoln blowing Abe? Sorry if this question comes across as crude, but I was genuinely wondering about it recently.
There was recently a fairly extensive discussion about the history of the practice around the world that included some excellent answers by /u/CommodoreCoco (South America), /u/lordtiando and /u/bigbluepanda (China), and /u/sunagainstgold (Rome), with some shorter answers touching on ancient Greece and Egypt, and possibly biblical entries. The gist of the answers is that oral sex long predates recent Western culture with evidence in writings, artwork, and graffitti, though some cultures looked down on men performing cunnilingus.
It didn't get as much into Europe and North American colonial era, which would be interesting to see answered here.