Hilarie Burton, Jeffrey Dean Morgan news: Baby girl on the way

Actor Jeffrey Dean Morgan (L) and his wife actress Hilarie Burton pose at the premiere of Marvel's "Ant-Man" in Hollywood, California June 29, 2015.REUTERS/Kevork Djansezian

It is a girl for celebrity couple Hilarie Burton and Jeffrey Dean Morgan. The latter accidentally revealed the gender of their second baby at the Supernatural Convention in New Jersey Sunday, Sept. 24.

Following the big reveal, the 51-year-old actor apologized to his wife for the slip of tongue. As expected, Burton was totally cool with it.

"Whoever took this picture?? Caught a moment... thank you. We shall cherish," Morgan wrote in the Instagram post's caption. "I texted @hilarieburton right after I spilled the little girl beans... and, as usual... she was a rock star. After all these years she's come to expect me to be a dope... thank god she gets it and loves me regardless."

Burton's pregnancy came to light when she and Morgan walked the red carpet together at this year's Primetime Emmy Awards. While there, the latter placed a gentle hand on her growing baby bump, which was hidden underneath the vintage Lanvin gown.

The baby girl will join their seven-year-old son, Augustus "Gus," whom they welcomed in 2010. In the past, Morgan candidly shared his experience as a first-time father.

"It's been spectacular," the "Desierto" actor said in an interview with E! News. "(Life is) a lot of not sleeping, and then our one adult night we come here... This is our date. Can you believe it?"

In the meantime, Morgan is spending most of his time filming for Brad Peyton's "Rampage." In it, he plays Agent Russell, a government agent with attitude who works for an organization called OGA. He is also set to reprise his villainous role as Negan in "The Walking Dead" season 8.

In the upcoming season, the character will go head-to-head against Rick Grimes (Andrew Lincoln) and the Alexandria survivors, including Daryl Dixon (Norman Reedus), Maggie Rhee (Lauren Cohan), and Michonne (Danai Gurira).

"The Walking Dead" season 8 will premiere on Oct. 22 on AMC.