'Always Sunny' stars welcome second son

Congratulations to South Philly native Rob McElhenney and wife/co-star Kaitlin Olson on the birth of their second child, Leo Grey McElhenney.

Olson tweeted this picture Tuesday night and said Leo was born April 5 after "23 very very long hours. We're in love."

Baby Leo has an older brother Axel Lee, born in Sept. 2010.