Charlie Sheen, 47, is going to be a grandpa.
Sheen's oldest child Cassandra Estevez, 28, is having a baby (Sheen's real name is Carlos Estevez). She is Sheen's child with high school sweetheart Paula Speert.
"It's like the world's going to crack in half," Sheen joked to David Letterman this week after he announced the news.
Sheen is a father of five who has been married three times. In addition to Cassandra, he has two daughters with ex Denise Richards -- Sam, 8, and Lola, 7 -- and twin sons Bob and Max, 2, with ex Brooke Mueller.