Kaley Cuoco and Henry Cavill take a hike

The Web is abuzz with a hot couple alert.

The Big Bang Theory star Kaley Cuoco and Superman actor Henry Cavill are dating, says, well, everyone.

Us quotes a source as saying "they're hot for each other." People quotes a source as saying, "they're having a great time."

The only shred of evidence is a tweet from Kaley in mid-June that hardly offers proof but does show she adores the "man of steel."

UPDATE 7/3: Splash News snapped the couple taking a hike together near Kaley's home in Sherman Oaks, Calif. People reports the two had sushi together after the workout.

As for Cavill, he broke up with Fast & Furious 6 star Gina Carano several months ago. So word is he's single.