Robert Downey Jr. may not be a superhero in real life, but he sure knows how to make his wife feel special!
E! News has exclusively learned that the Iron Man star threw a star-studded bash for his wife Susan's 40th birthday, hosting a celebration at Cavallo Point near Sausalito, Calif. where guests, including Justin Theroux, Gwen Stefani, Gavin Rossdale, Gwyneth Paltrow, Jon Favreau and Reese Witherspoon, spent the entire weekend relaxing at a resort spa.
"It was a great weekend for Susan, and Robert went all out to make sure she knows how special she is," a source exclusively tells E! News of the getaway. "Around 50 of their closest friends came up for the weekend and stayed at the hotel in historic houses. It was a very relaxing weekend and there was a lot of time for people to catch up."