Mac and Dee had a baby....another one! Rob McElhenney and Kaitlin Olson of the hit FX comedy, Always Sunny In Philadelphia announced that they welcomed their second son on Thursday April 5.

Olson revealed to People magazine that she gave birth in their home in Los Angeles. The couple named their son Leo Grey McElhenney. Leo was born at 1:15 a.m. on April 5. The baby weighed 8 lbs. 5 oz. and is 20 inches long. Leo joins 19 month old brother Axel Lee.

According to Nameberry.com, the name Leo is of Latin origin and means lion. In 2010 the name was ranked at number 193 for popularity.

The proud parents told People magazine that they are overjoyed.

McElhenney and Olson married in September 2008 in Malibu. The couple have been working on It's Always Sunny in Philadelphia since 2005. McElhenney is the creator of the series and plays Mac, a co-owner of Paddy's Pub with his friends Dennis (Glenn Howerton) and Charlie (Charlie Day). Olson plays Dee, Dennis' twin sister. Danny DeVito also stars on the show as Frank, Dennis and Dee's father.