Taylor Lautner has to be ''careful'' when he meets girls.

The 'Twilight Saga' actor - who has been romantically linked to both Taylor Swift and Lily Collins in the past - is often on ''guard'' when he makes new female friends, but doesn't want to be too difficult to get to know otherwise he would never make new friends.

He said: ''I do have to be more careful. I would be lying if I said that I don't guard myself more than I used to, but I don't want to be too guarded.

''If you have so many walls up that you can't even make new friends or find new relationships, that would be a bummer.''

Taylor, 20, is also unsure if he believes in love at first sight, and constantly changes his mind about it.

He told LOOK magazine: ''I'm still figuring that one out. I go back and forth on that. Sometimes I say I do and sometimes I'm not sure. I definitely think I need a few more years under my belt to fully know if I believe that or not.''