Charlie Sheen is about to become a grandfather!!

The 47-year-old actor’s oldest daughter, Cassandra Estevez, is pregnant with her first child, Sheen confirmed during his Monday appearance on “The Late Show with David Letterman.”

The Anger Management star’s ex-wife Denise Richards tweeted, “I guess some of you have heard… @CharlieSheen is going to be a Grampa…yes GRAMPA! his beautiful daughter Cassandra is gonna be a mama.”

Charlie and Denise, who were married from 2002 to 2006, have two children together, Sam, 8, Lola, 7. The actor also has 3-year-old twin sons, Bob and Max, with Brooke Mueller.

Cassandra’s mother is the Sheen’s high school girlfriend Paula Profit.

On the video below – Sheen also talks about ‘Two and a Half Men’ and is breakdown in 2011!!

On Wednesday Sheen will appear on The Dr. Oz Show, getting lectured about his reckless living, including drug abuse and smoking.