Insider spills how sparks between Harry Styles, Olivia Wilde flew on movie set

Harry Styles and Olivia Wilde's romance buzz has riled up much of the showbiz world.

According to sources, the two have been seeing each other 'for weeks' now.

Meanwhile, a PEOPLE insider revealed that the Harry and Olivia's close friendship blossomed quickly into a romantic relationship on the sets of a movie.

"What started out as a close friendship, quickly turned romantic," the source said. "Everyone saw it coming. During breaks, he's hasn't been able to stay away and visited her trailer."

The duo was seen holding hands while attending a friend's wedding together over the weekend.

"They were in Montecito, California this weekend for a wedding," the source said. "They were affectionate around their friends, held hands and looked very happy."