Courtney Mazza welcomes baby boy with husband Mario Lopez

Mario Lopez and his wife Courtney Mazza welcomed their second child, a baby boy, on Monday.

The couple opted to keep the sex of the baby a surprise until he was born.

This anticipation is killing me...

#BabyLopezNumber2

— Mario Lopez (@MarioLopezExtra) September 10, 2013

Lopez had to rush to the delivery room from the set of "The X Factor" once he learned his wife was in labor.

"Whoa. Cutting it close," Lopez, 39, wrote. "Just wrapped @TheXFactorUSA & I'm rushing to the hospital. Baby Lopez #2 is coming tonight! Baby better wait for me."

He revealed the name and sex of the baby on Twitter shortly after Dominic was born.

It's a boy!!!!!!!!!!!!!! Please welcome Dominic Lopez to the world! Couldn't be happier... @CourtneyMLopez & baby are doing just fine... :)

— Mario Lopez (@MarioLopezExtra) September 10, 2013

Now their daughter Gia is big sister to baby Dominic Lopez. Fellow "Saved By The Bell" stars have sent congratulatory tweets all day. Gia will turn three on Thursday.