Hollywood star Robert Downey Jr. marked a special milestone with his wife, Susan Downey, whom he lovingly called “lioness”, celebrating 21 years together.Tagging himself as the “adult cub,” the star expressed gratitude for being guided on a path of “righteous humility” alongside his “SuperBuddy.”Downey Jr. took to Instagram, where he shared two images, including a picture of an ace and queen card from a deck of playing cards, as he celebrated 21 years with his wife, Susan Downey.“Her to whom all is owed…The great joy of being led on a path of righteous humility is mine. She-the lioness – Me-the adult cub / recipient of 21 trips around the sun with my SuperBuddy,” he wrote as the caption.Downey Jr. proposed to Susan on November 5, 2003, the night before her 30th birthday. They were married in August 2005, in a Jewish ceremony at Amagansett, New York. She gave birth to their son, Exton Elias Downey, in 2012, in Los Angeles, California.In 2014, Downey Jr. announced via his Facebook and Twitter that he and his wife were expecting a daughter in November. Their daughter, Avri Roel, was born on November 4, 2014.Talking about Downey Jr. he is one of the highest-grossing actors of all time. The star is known for his versatility across roles, he is the recipient of various accolades, including an Academy Award, a Daytime Emmy Award, three Golden Globe Awards, and two British Academy Film Awards.He will soon be seen playing Doctor Doom in the upcoming Avengers: Doomsday, a superhero film based on the Marvel Comics superhero team the Avengers. It is intended to be the sequel to Avengers: Endgame and the 39th film in the Marvel Cinematic Universe (MCU).Directed by Anthony and Joe Russo, and written by Michael Waldron and Stephen McFeely, the film features an ensemble cast led by Robert Downey Jr. as Doctor Doom. In the film, the Avengers, Wakandans, New Avengers, Fantastic Four, and the X-Men converge from different universes to face Doom.