Published photos of Charlize Theron, 38, and Sean Penn, 53, vacationing in Oahu have led the media to speculate about a budding romance between the two actors, according to USA Today.

The photos show Penn surfing, while Theron relaxes on the beach. According to the Daily Mail, the pair stayed at Penn’s beachfront property on the island.

Penn and Theron returned to Los Angeles from Hawaii aboard the same flight on New Year’s Day, a witness told E! Online.

The two first sparked romance rumors in 2010, after dining together following her split from long-term boyfriend, Stuart Townsend, and his divorce from wife, Robin Wright.

The actors’ reps had no comment.