After leaving one of her favorite restaurants in Malibu, Giorio Baldi, this past Wednesday (3/22), the short shorts wearing Rihanna is rumored to have stopped by Ashton Kutcher's house around midnight...and wasn't spotted leaving until 4am!

She did post a number of tweets on her Twitter account, one of them reading: "Mama needs a break!" when asked by a fan if she was going to be clubbing that night.  She was at Kutcher's house when she made that tweet, so who knows, maybe Ashton was able to offer her some much needed down time, or maybe they partied in private. 

Again, who knows?