President Joe Biden on Monday joined Threads, Meta’s X competitor, and in his first post poked fun at his age, having celebrated his birthday the same day. “I turned 81 and all I got was a new social platform!” he wrote, along with a photo of him in front of a brightly burning cake. “Thanks for the well-wishes, folks. And to the workers at the birthday candle factory, I hope your union got you overtime.” As the oldest person to have been president, Biden has lately been making light of his age, as many donors have suggested. At the annual turkey pardoning ceremony Monday, he quipped, “As much of you know, it’s difficult turning 60.” The move comes as advertisers flee X after owner Elon Musk denied endorsing an antisemitic statement.