Are 'Game of Thrones' couple Kit Harington and Rose Leslie dating in real life?

As bastard Jon Snow and wilding Ygritte, "Game of Thrones" co-stars Kit Harington and Rose Leslie almost melt the ice beyond The Wall with their sizzling-hot chemistry.

Maybe they're not acting.

TMZ reports that the couple were recently spotted on a dinner date in London, holding hands and kissing.

Or maybe they're just researching their roles? When "Game of Thrones" returns to HBO in March, the fiery redhead, who also played housemaid Gwen in "Downton Abbey's" first season, will -- spoiler alert! -- seduce the Night's Watch spy into breaking his vow of chastity.