Robert Pattinson has a weakness, Taylor Lautner, both on and off screen.

In the "Twilight" movies Lautner is RPatz competition. Bella (Kristen Stewart) also loves him.

But Pattinson admitted recently that he also fears his co-star off screen.

He said in a recent interview that he is terrified of Lautner's martial arts moves.

Lautner, who plays a roaring werewolf in "Twilight", has been studying karate since was six years old.

In the movie he belong to the pack of werewolves who keep vampires away from their land, and mostly by slaughtering them. So in both lives Robert has be to maintain his distance.

Secretly maybe RPatz fears that KStew may also fall for Lautner's muscles, handsome looks and charm.

Stranger things have happened!

We think he'd kick your ass Robert!

Watch out.

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