Jimmy Kimmel revealed in May that his newborn son, baby Billy, had undergone open-heart surgery shortly after his birth and over the weekend, the late-night talk show host offered an update on Billy's health.

During an event for Alex’s Lemonade Stand Foundation in Los Angeles on Saturday, September 9, Kimmel spoke to Us Weekly about his youngest child.

“Billy is doing well. He’s right there!” he told the magazine. “He’s got to have another operation soon, but he’s doing well.”

According to Kimmel, who also shares an older child with wife Molly McNearney, the Los Angeles benefit event was Billy's first red carpet appearance.

“He seems to be strong,” Kimmel added. “He pulls hair, that’s for sure!”

Kimmel and McNearney attended the event on Saturday in an effort to support to organization, which raises funds for childhood cancer research.

“Alex’s Lemonade is a great charity. There’s a great story behind it. It really was started by a little girl, not by a group of adults. Sadly she passed away, so her parents carried on this tradition. And now, really, the greatest chefs in the United States gather to do these events,” he said.

In May, Kimmel opened up to his Jimmy Kimmel Live audience about the heartwrenching moment that his son went under the knife just hours after he was born due to a condition described as "tetralogy of fallot with pulmonary atresia."

"On Monday morning, Dr. Vaughn Starnes opened his chest and fixed one of the two defects in his heart. He went in there with a scalpel and did some kind of magic that I couldn't even begin to explain," Kimmel said. "He opened the valve, and the operation was a success. It was the longest three hours of my life."

Tags: Jimmy Kimmel