Sean Penn showed up to "The Late Show" a little more relaxed than usual.
During his guest appearance on Monday, the 57-year-old actor admitted he was still experiencing the effects of a sedative he took after a recent flight.
"You've inherited a little of the Ambien I had to take to get to sleep after a red-eye last night," the "Mystic River" star said.
"So, in other words, you're still a little bit on the Ambien train right now?" host Stephen Colbert asked him.
"A little bit," he replied.
Penn then proceeded to light up a cigarette right in the middle of the interview.
"I thought you might," Colbert said, whipping out an ashtray.
At one point, Colbert actually asked the actor to stop smoking.
"I wish you'd move on. Please don't smoke anymore," the late-night host said. "I don't mind. My parents smoked when I was a child, so it gives me happy memories to smell cigarette smoke. But we want you to be around for a long time and those things are bad for you."
"This is job security for oncologists," Penn replied.
The actor put out his cigarette but eventually lit up another.