Robert Downey Jr. pokes fun at Tom Hiddleston, Taylor Swift relationship

Robert Downey Jr. pokes fun at Tom Hiddleston, Taylor Swift relationship

Tony Stark and Loki are canonical enemies in Marvel's Cinematic Universe, but Robert Downey Jr. and Tom Hiddleston are on good terms. See RDJ's Instagram welcome for Hiddleston.

Hiddleston, star of AMC and BBC's The Night Manager, joined Instagram earlier Tuesday and posted a shot of him in costume as Thor's brother: "He's back!" he wrote.

Downey Jr. dug into Hiddleston's recent history of outfits and picked a photo of the "I [heart] T.S." shirt Hiddleston wore on the 4th of July, referencing his girlfriend Taylor Swift. The Iron Man star opened his arms in a very Tony Stark way.

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"Join me in welcoming the biggest T. Stark fan of them all to Instagram! @twhiddleston" Downey Jr. wrote.

Join me in welcoming the biggest T. Stark fan of them all to Instagram! @twhiddleston

A photo posted by Robert Downey Jr. (@robertdowneyjr) on Aug 9, 2016 at 3:09pm PDT

Hiddleston and Loki will return to the MCU for Thor: Ragnarok, out Nov. 3, 2017. Meanwhile, Stark/Downey Jr. just appeared in this summer's Captain America: Civil War and will pop up again in next summer's Spider-Man: Homecoming