Sarandon, 69, attended the ceremony on January 30 in a cream suit with just an inner wear underneath her blazer, leaving her ample cleavage on show.
She was there to present an In Memoriam tribute to stars including the late David Bowie and Alan Rickman, who both passed away last month (Jan16), and she was also nominated for her role in The Secret Life of Marilyn Monroe.
Now Robbins has leapt to the defence of his mother, telling she is "right to be proud of her body".
"If she wasn't 69 no one would be saying anything. It's ageist and sexist to attack her," he added.
"She's a beautiful woman. If Piers Morgan wants to make fun of my mother and focus his energy on that, then power to him.
