29-year-old Katy Perry was the actual guest that was announced by Ellen to appear in an episode of her show, but 36-year-old Mayer, who is in a relationship with Perry, made a surprise appearance in the show as well.
"Is he as romantic as his music is?" DeGeneres asked Perry in the Ellen Show.
"Very thoughtful, very creative," replied Perry to Ellen's question.
Ellen joked that Perry didn't actually say Mayer was romantic though.
But, Perry said that to her, when someone is thoughtful, that's romantic.
"The best Christmas gift is a thoughtful one, you know, one that's romantic that has been thought about and spent a lot of time over. It's not just like a label or a thing," explained Perry to DeGeneres.
Katy also revealed that sometimes they don't talk at home. But, it's not because they are fighting or anything like that. It's just that as singers, they have to take care of their voices. That's why they go on a complete vocal rest and spend quiet time at home with each other. According to Katy, even whispering is not allowed.
During these quiet times, the couple would communicate through an iPad. Ellen jokingly suggested that they should play Pictionary and Katy said that they should learn sign language.
Katy also made a jab at Kim Kardashian's appearance in Kanye West's "Bound 2" music video. Perry commented about Kardashian's hair and how it was blowing in the wrong direction. She compared that to their music video and said that at least her hair was blowing in the right way.
Mayer also talked about Katy's sense of humour.
"This is why voice rest is just fine," said Mayer in "The Ellen DeGeneres Show."
"You get these chestnuts," he added.
Mayer and Perry's single "Who You Love" features other real-life couples and is about the trials of a relationship and what you must do to preserve that special bond.
Katy further revealed to Ellen why they click as a couple.
"We have a lot of fun. You know, we have music as an understanding and love between each other, and we connect, and you know it's like he understands what I do because he does the same thing. And so after a long day, if it's been tough, I don't really have to go into it. He just gets it. You know, so it's nice with that understanding," said Perry to Ellen in a report from Entertainmentwise.
Click HERE to see photos of Katy Perry in "The Ellen DeGeneres Show." Check out the music video of John Mayer and Katy Perry's "Who You Love" single below: