The clues were always there. Bert and Ernie have been living together for 31 years. They like to wear flamboyant "his & his" pyjamas. And (here's the clincher) they tuck themselves up together each night in the same bed.
It has, however, taken a careless status update on Twitter to convince America's gay community of what they suspected all along: that two of Sesame Street's best-known characters are preparing to venture out of the closet.
Bert recently used the social networking site to discuss an A-Team parody which will feature on the children's TV show next month. "Ever notice how similar my hair is to Mr. T's?" he asked. "The only difference is that mine is a little more 'mo', and a little less 'hawk'."
The comment understandably passed below the radar of many readers. But it sparked huge intrigue in certain gay circles, where "mo" has for years been a discreet slang term meaning "homosexual".
Writing on the influential gay blog AfterElton.com, Ed Kennedy swiftly noted that the tweet came during a week when many US cities were hosting their annual Gay Pride celebrations. "The people at Sesame Street are way too clever for their own good," he claimed.
At the weekend, the Los Angeles Times weighed in on the debate, offering a lengthy analysis of whether, in the paper's own words, America's most influential children's TV show is being "brought to you by the letters G-A-Y".
By way of evidence, the paper cited recent guest appearances by lesbian comedian Wanda Sykes, the gay actor Neil Patrick Harris, who played the "shoe fairy", and Will.i.am, the front-man of the Black Eyed Peas, who sang What I Am, a gay anthem.
The programme recently satirised True Blood, a TV show which has a huge gay following. Katy Perry, whose most famous song is I Kissed a Girl, was also recently given a guest spot, though it was not broadcast due to concerns about her revealing outfit. All of this convinced a spokesman for the Gay and Lesbian Alliance Against Defamation to applaud Sesame Street for opening another chapter in its "long history of teaching children about diversity and acceptance".
With an eye, perhaps, on audiences in less cosmopolitan corners of America, a spokesman for the show meanwhile declined to comment on Bert's sexuality, saying ambiguously: "our programming has always appealed to adults as much as children".