Ashton Kutcher appeared on The Tonight Show with Conan O’Brien Monday night, and host Conan O’Brien introduced him as, “The most popular Twitterer in the world.”

During their conversation, Kutcher referred to himself as, “the uncompensated spokesperson for Twitter—I don’t own like a piece of the company, or anything like that.”

While discussing a picture Kutcher tweeted out of his wife, Demi Moore, Kutcher said:

It was a bikini, not underwear—it was white, so people might have confused it. She was ironing my pants, I took a picture of it and I asked her before I sent it out to the world. It’s a good butt! I mean, she’s got a really good butt! But it was covered. It was in a bikini. You can see that at the beach.