The 54-year-old actor showed up to WE Day at the Forum in Los Angeles, California, on Thursday, and when asked how fatherhood was treating him, Stamos mused, "I'm good. I'm a little tired. I think I've got a little poop on this suit."
Stamos then shared with ET a sweet moment that he recently had with his newborn son. "I woke up this morning and I sang him 'House at Pooh Corner,' the Christopher Robin [song]," he recalled. "I started crying. It was great."
The Fuller House star also praised his wife for how she handled the delivery. "My wife was so beautiful and so graceful through it all, like she does life. I mean, she just kind of breezed through," he said of McHugh's labor. "I hate to tell women, but she did it in about 20 minutes. It happens so fast and then they were like, 'Take pictures! Grab her leg!' And then it was over, but it was just beautiful."
As for whether Billy has inherited Stamos' great head of hair, the proud father quipped, "He has pretty good hair. I'm pretty impressed."
Continuing to brag about the new addition to his family, Stamos added, "It's more beautiful than I imagined. Everything is more colorful, more exciting. Music, you know, sounds better. He's just a beautiful little boy."
For more with Stamos and his life as a first-time dad, check out the video: