Why Kat Dennings and Fiancé Andrew W.K. Already Wear Their Wedding Bands

The couple got engaged last May.

Kat Dennings just couldn't wait to put on her wedding ring. The 35-year-old Dollface actress appeared on Monday's episode of The Ellen DeGeneres Show, and explained why she and her fiancé, Andrew W.K., are already sporting their wedding bands even though they haven't tied the knot.

"We're not married yet, but we went to buy our wedding bands and we were like, 'Why don't we just wear them? Who cares!' And that's the end of that story," Dennings quipped. "Why not? There's no rules. No rules, just right."

Dennings and W.K. went public with their romance last May, the same month that the 42-year-old singer popped the question. The actress knew it was meant to be when W.K., who's allergic to cats, wound up not being allergic to her beloved feline, Millie.

"Andrew is the first, and the luckily the last, man Millie has ever loved," Dennings gushed. "She has despised every other romantic person in my existence. She once waited overnight until an ex left the house and she peed on his pillow like it was her job."

Millie is so taken with W.K., in fact, that she once picked him over Dennings.

"The other day she was scratching at the bedroom door and I assumed she wanted to see her mother, me," Dennings recalled. "She ran right past me and over to Andrew. That was the first time that has ever happened. It was pretty special."

Prior to her engagement, Dennings told ET why she tends to keep her private life out of the public eye and off of social media.

"I don't share most things and it's not because I I have any secrets or anything, it's just that I have found that when I've shared very personal things, like, I'm dating or whatever it is, like, it kind of feels icky," she told ET. "... I've just learned over the years... it doesn't feel good for me."