I've certainly heard these corrugated cup-coverings casually called coffee condoms by college kids around campus (with the occasional “ribbed for her pleasure” snickers).
As might be expected of a coinage like this, Urban Dictionary offers the most baldfaced definition of this bit of street slang:
Coffee Condom
The name for the sleeve that goes around your handle-less paper coffee cup to insulate the drinker's hands from hot coffee.
Similar to how a latex condom is designed to protect you from sexually transmitted diseases the "coffee condom" is designed to protect your hand from the hot cup of coffee.
Smithsonian Magazine from 2013-08-13 had an article on “How the Coffee Cup Sleeve Was Invented” containing a more detailed history of this device, including this small bit:
Jay Sorensen invented the Java Jacket in 1991 as a solution to a common problem—hot coffee burns fingers. The idea emerged in 1989 when he was pulling out of a coffee shop drive-through on the way to his daughter’s school and a coffee spill burned his fingers, forcing him to release a scalding cup of coffee onto his lap. At the time, he was struggling as a realtor in the years since closing his family-owned service station in Portland, Oregon. While the coffee accident was unfortunate, it gave him the germ of an innovative idea: there had to be a better way to drink coffee on the go.
Sorensen ended up patenting his Java Jacket idea, and he sells a billion (B-I-L-L-I-O-N) of these a year. But the one you get at Starbucks is ever so lightly different enough that they got their own patent after Sorenson got his. An earlier patent for such a device was granted back in 1964:
And there have been many others besides that one. The Smithsonian article also mentions one called a portable coaster back in 1947.