Maybe it was London Fashion Week that started the trend, but Bradley Cooper has been showing up to events more commonly with Suki Waterhouse by his side.

And he was recently spotted with the model outside of his mother's house, said the Daily Mail.

Cooper, 39, and Waterhouse, 22, arrived separately and met on the driveway. Cooper's face was hidden by his helmet, which he paired with a leather jacket and green pants while Waterhouse wore a short, breezy dress.

Cooper looked heavier than usual. He has gained 40 pounds to play Chris Kyle, a real-life Navy SEAL for the movie "American Sniper."

His co-star Eric Close has said that Bradley has completely changed his diet.

"He's really been working hard," said Close. "He looks great. He's really taken on this character, [Bradley] really takes this story personally and wants to do an honorable job for Chris's memory and for his family."

The movie spans Kyle's career, in which he killed more than 150 people. He served four tours in Iraq. Insurgents nicknamed him the Devil of Ramadi, and he was killed in 2013.

The Clint Eastwood movie is currently being filmed in Santa Clarita at the Blue Cloud Movie Ranch. Sienna Miller plays his wife, and she was seen wearing a baby bump for the role. She says Eastwood has taken to calling Cooper "Her Highness" and "The Duchess" because he takes so much time in the makeup chair.

"It started because Eastwood thinks Cooper takes too damn long in the makeup chair," a source said. "And lately, whenever he needs Bradley and co-star Sienna Miller, he yells -- 'are the girls ready?'"

And when Cooper is not busy filming the movie, he's been spotted with Waterhouse.

The two recently attended the Met Gala, though they didn't pose together. After the gala they were seen looking a little more dressed down and holding hands. The model wore a dress with a criss-cross neckline, which she covered with a part-white and part-purple coat.