There is some rivalry between Twilight co-stars Kellan Lutz and the franchise’s leading actor Robert Pattinson.

Lutz – who is the new face of Calvin Klein’s latest underwear range – admitted he is envious of the English actor’s abilities.

“He’s such a talented motherf**ker,” said hunky blue-eyed Kellan. “I wonder how I can get what he has.”

But one thing Kellan does have over Robert is his buff physique. “He asks me what I do to work out because he wants man boobs like me,” joked Lutz.

“I just tell him I like doing push-ups.”