American star Demi Moore is reportedly upset at Rihanna, after rumors spread the singer is in a relationship with Demi's former husband, actor Ashton Kutcher.

"Daily Mail" British newspaper noted Rihanna was at Ashton's house late at night and the two are thought of to be involved for about eight weeks now.

The actor would have been involved with Rihanna just a short time after the scandals of him cheating on his wife spread. The scandal and aftermath led to the depression of Demi, who was recently checked into a rehabilitation center.

-ATC