'Avengers' co-stars funny birthday wishes for Robert Downey Jr

Robert Downey Jr has turned 52 and his 'Avengers' co-stars wished him on his birthday in many hilarious ways.
Actors Chris Hemsworth, Chris Evans and Mark Ruffalo took to Twitter to give a shout-out to Downey Jr on his birthday.

"Happy birthday @RobertDowneyJr you haven't aged a day since this picture," tweeted Hemsworth, alongside a funny photograph, which shows the birthday boy donning a wig and appearing old and wrinkly with the 'Thor' star giving a thumbs-up.

While Evans wrote, "Happy birthday to the legendary @RobertDowneyJr. Mentor. Life-saver. Friend. Hope your birthday is like a giant kiss on the lips!"

The 'Captain America' star posted a GIF alongside his sweet message which shows him going in for a smooch with Downey Jr dressed as Iron Man.
Ruffalo also took to Twitter and wrote, "Happy birthday @robertdowneyjr! A picture is worth a thousand words. #sciencebros4ever."

The actor, who plays The Hulk in the Marvel franchise, shared a picture where he is sitting in Downey Jr's lap and gazing lovingly in his eyes, along with the other 'Avengers' actors Scarlett Johansson, Jeremy Renner, Evans and Hemsworth watch the scene unfold in faux surprise.