Justin Long on Filming with Drew: "It Made Her So Much More Beautiful"

There were ups and down for Justin Long while filming his new movie Going the Distance. The positive was working with his on-and-off girlfriend Drew Barrymore, while the negative was getting naked in front of Christina Applegate!

OK! GALLERY: DREW & JUSTIN GET COZY ON THE DISTANCE CARPET

At the London premiere of Going the Distance, Justin told reporters (via The Gossip Girls) that working with Drew made him love her even more.

"She's so funny, insanely funny. But I also got to see a side of her during this movie, which I hadn't seen, because I'd never known her in a professional capacity," Justin explained. "I got to see how she treated the people that she's working with and it made her so much more beautiful. She's lovely to everyone — to PA's, studio people, no matter where you are in the hierarchy. It's rare."

OK! NEWS: DREW BARRYMORE DISHES ON PHONE SEX EXPERIENCE

But his experience working with Christina wasn't as positive! He had to film a full-frontal nude scene in front of her!

“I was sort of exposing myself to someone I grew up watching," Justin told reporters. "Really weird. And while we were shooting! I’m kidding.”

OK! NEWS: JUSTIN LONG'S GOING THE DISTANCE TO DISCUSS RELATIONSHIP WITH DREW

But really, Justin only has wonderful things to say about his co-star Christina and her husband Martyn LeNoble's exciting baby news!

"It's so great. She's the best and no one that I know is more deserving after what she's been through, Justin said (via The Press Association). "She's been through a lot and I'm so happy for her."

"And Martyn, she's got an awesome husband," he added. "He's missing a tooth but he doesn't care. He rules."

OK! GALLERY: DREW & JUSTIN ENJOY A LITTLE SMOOCH WITH THEIR LUNCH

And Drew is just as excited for Christina as Justin!