As a special surprise for her audience on Tuesday, December 11, Ellen DeGeneres invited her friend and neighbor Ashton Kutcher to join her as co-host on her daytime talk show. Kutcher seemed in great spirits, laughing about neighborly in-jokes, but about one issue he was very serious: that his two-year-old son can walk.

Apparently, Kutcher and his wife, Mila Kunis, often go for walks past Ellen's house in the morning with their dog and kids in tow. During one such excursion, Ellen happened to pop her head outside to say hello, only to observe that Kutcher's son always seemed to be riding in Kutcher's backpack instead of walking.

As Ashton tells it:

"I now have a complex about this, because I have one of those hiking backpack things, so I put him in the hiker to go down to the beach so we can actually go down the beach, otherwise it's a whole wrangling session with the kid. And then you came out and you were like, 'Oh, does he walk?' And I'm like, 'Yes! He walks!'"

Ashton Kutcher Forces His Son to Walk by Ellen and Portia's House youtu.be

Now, during morning walks, Kutcher always makes sure to take his son out of his backpack and make him walk his very best walk past Ellen's house.

Naturally, he wants to prove a point:

"So now I take him out of the thing once we get to purview of your house, and I'm like, 'Go, go! Run, little sucker!' And I'm trying to dish him along so I don't have to hear about it anymore. This kid's going to be an Olympian, man, because I'm going to be behind him like, 'To Ellen's house!'"

Ashton and Ellen have been neighbors for a long time and have developed a friendship that always makes for fun guest appearances. Earlier this year, Kutcher made a surprise appearance on the show, where he shocked Ellen with a $4 million dollar donation to her wildlife fund.

During the same episode in which Kutcher told the story of his son's walking, he spoke with Ellen about his love for Dax Shepard.

The audience got a taste of Ellen's Game of Games holiday spectacular!

As much as the internet loves Ellen solo, they couldn't get enough of this delightful pair of neighbors.

The pair were later joined by Amy Adams, who reminisced about her guest appearance on an old episode of That '70s Show. Adams was on the show to promote Vice, the new movie in which she stars as Lynne Cheney, wife of Vice President Dick Cheney.

VICE Official Trailer (2018) Christian Bale, Amy Adams Movie HD youtu.be

It seems Ashton and Ellen are going to be friends forever...as long as Ellen can stop herself from making fun of Ashton's son's walking habits.