Abbreviating conversational phrases with acronyms isn’t unique to this decade or even this millennium. Friends and lovers exchanged hand-written letters with truncated sayings—both sweet and pornographic—as far back as Biblical times.
And while many early acronyms were used to save time, others were codes, meant to only be decipherable to the recipient. This was especially rampant in the run-up to and during World War II, when troops wanted to get a rise out of their sweethearts back home. They developed their own cryptic acronyms, many of which were sexually graphic, and scrawled them on the back of love letter envelopes.