Kristen Stewart and Robert Pattinson's relationship has been rocked by allegations that Kristen has cheated.
The pair - who play star-crossed lovers Bella Swann and Edward Cullen in the hit Twilight films - have never confirmed they are a real life couple, but are believed to have been dating for at least three years now.
American magazine Us has posted a picture on its website of Kristen, 22, on its cover in an intimate embrace with 41-year-old married man Rupert Sanders, who directed her in her latest movie Snow White And The Huntsman.
The magazine claims to have more "steamy" pictures of the pair in its latest issue.
Rupert is married to British model and actress Liberty Ross, 33 and has two children, aged seven and five.
None of the parties involved have commented.
Liberty appears to have since deleted her Twitter account.