The 37-year-old actor tied the knot with the Twilight beauty in April, 2015 after less than a year of dating, but Kat thinks their union was meant to be because they share similar values.

"Why I think they're so perfect is because of their philanthropy," she explained to People magazine. "They have the same values when it comes to people, how you treat people, how you treat animals, how you treat the world, the environment. I mean, they're really perfect together. I'm like, 'Thank God you guys found each other because I don't know what you would do without each other.' They're perfect."

The 26-year-old has grown close to Nikki, 28, through her relationship with Ian, and Kat credits her with inspiring her multiple body piercings.

"Nikki is amazing, and we are very, very close," she continued. "All of my ear piercings, you can thank her. She didn't pierce them, but she's got like, crazy ear game, and it's really cute when best friends take inspiration from each other."

Kat also discussed the news of the hit show coming to an end after series eight, an announcement made by show creators at Comic Con in San Diego, California last month (Jul16).

Having been part of the show since the pilot, Kat knows it will be a "bittersweet" moment when she shoots her final scenes.

"I feel like they're going to be ready for this show to come to a close, to wrap up storylines more than they would have been in season six," she said. "At least I know my fans are ready to see some final and new developments. I hope for the biggest and most incredible ending, and all the people that were in the beginning to end the show together. That's my goal."