Lutz, who plays vampire Emmet Cullen in the hit movie franchise, is the latest Hollywood hunk stripped bare for the fashion house's underwear campaign.
And Reed, who plays his on-screen sister Rosalie, is proud of her pal's sexy shots.
She tells E! Online, "I think he looks fantastic. I'm actually really proud of him.
"It takes a lot of balls, no pun intended, to stand and pose like that. I wouldn't have the guts to stand there naked like that."
Lutz recently revealed he wanted to follow in the footsteps of Mark Wahlberg - whose famed Calvin Klein underwear campaign in the '90s led to a huge film career.