Shia LeBeouf and Megan Fox
Characters: Sam Witwicky and Mikaela Banes
Movie: The Transformers (2007), The Transformers: Revenge of the Fallen (2009)
We knew for sure that the Even Stevens days were long gone when Shia LeBeouf accidentally purposely accidentally admitted to Details that he and Megan Fox had hooked up during the filming of the second Transformers movie.
In case you were underground or in outer space back in 2007, the first two parts of the franchise feature LeBeouf's Sam and Fox's Mikaela as friends-turned-lovers on a mission to save the world. Sam knows a big secret that is the planet's final hope, while Mikaela knows how to steal cars and look like a model dressed as a mechanic for Halloween.
Of course, the question on every gossip monger's lips was whether Fox had cheated on current husband, Brian Austin Green. LeBeouf's response? Repeating "I don't know" about 12 times. Who would have ever thought that the curly-haired nerd from our childhoods could get into so much trouble?