Taylor Lautner has opened up about Kristen Stewart's cheating scandal.

The 'Twilight' actor has broken his silence about his co-star's "momentary indiscretion" - when she was caught cheating on Robert Pattinson with married 'Snow White and the Huntsman' director Rupert Sanders - and doesn't know whether the trust can ever be regained in a relationship.

When quizzed on her infidelity, Taylor said: "To be honest, I've never been involved in any of those situations, so I don't know [if trust can be regained]. It would be just a guess and a shot in the dark, and I don't want to give that if I haven't even been there myself."

The Hollywood hunk was quick to defend his co-star Kristen -- who plays Bella Swan, his werewolf character Jacob Black's love interest, in the film franchise -- and insisted he is "proud" of every decision she makes.

He said: "Kristen is fantastic at everything she does. I'm always proud of her."

The 20-year-old actor is sad his time in the vampire series is coming to an end, but is looking forward to exploring new roles after working on five 'Twilight Saga' movies.

Taylor revealed: "I'm extremely said that it's ending. It's been such an amazing part of my life. But on the other hand, I'm looking forward to that next chapter and contenting to challenge myself and do different things."

The final 'Twilight Saga' movie, 'Breaking Dawn: Part 2' is released on November 16.