Third Child on the Way for Chad Lowe

The couple are already parents to daughters Fiona and Mabel

David Livingston/Getty

Chad Lowe was keeping a secret of his own: There’s another baby on the way!

The Pretty Little Liars star and his wife Kim are expecting their third child, he confirms.

The couple are already parents to daughters Fiona, 3, and Mabel, 6.

“We are so thrilled that our family is growing,” the actor and director tells PEOPLE exclusively.

“Mabel and Fiona can’t wait to be big sisters … Kim and I are studying up on zone defense!”

“Baby number 3 due this spring!” Lowe, 47, tweeted along with the hashtag #blessed.

And with Kim’s previous pregnancies under his belt, Lowe, who recently directed episodes of Bones, as well as his own show, definitely knows the drill.

“I’m trying to bank some sleeping hours, which is a little tough,” he told PEOPLE shortly before Fiona’s birth.

“I have been out buying a lot of stuff to organize [everything] we have. It is amazing how much stuff babies need.”

The family with Chad’s brother Rob earlier this month – Axelle/Bauer-Griffin/FilmMagic

The Lowes began dating in January 2007 and tied the knot in front of family and friends during an oceanside ceremony in Los Angeles in August 2010.

— Anya Leon with reporting by Sarah Michaud