In case you missed it, Tom Hiddleston made his long-awaited Instagram debut today with a shot of him in his Loki wig, teasing his return to the Avengers universe in Thor: Ragnorak. And while his girlfriend Taylor Swift reportedly has yet to follow him on the app (at least, thus far), his Marvel brother-in-arms Robert Downey Jr. has already sent him a warm, hilarious welcome.

“Join me in welcoming the biggest T. Stark fan of them all to Instagram! @twhiddleston,” Downey Jr. wrote, accompanied by a blurry paparazzi pic of the now-infamous “I [heart] T.S.” tank top Hiddleston wore during the early days of his and Swift’s whirlwind romance.

Right, RDJ ... because T.S. definitely stands for Tony Stark. Right.

Hiddleston has yet to respond to Downey Jr.’s joke, but here’s hoping they address it when Ragnorak begins its press rounds. Sure, it doesn’t release in theaters until next November, but I have a feeling this joke will hold up just fine.