Leighton Meester Jokes Adam Brody Is a 'Dummy' Father on TV — But a 'Grown-Up' Dad in Real Life

Leighton Meester is happy that Adam Brody gets to be her "baby daddy" both in real life and on television.

The couple, who are expecting their second child together, reunited on the small screen Wednesday for the Single Parents season 2 finale, where Brody returned as Derek, the ex and baby daddy of Meester's lead character, Angie.

While the cast of the ABC sitcom filmed Wednesday's finale in February, Meester shared with Entertainment Tonight what it was like having her husband appear on the show.

"He is the baby daddy. In real life and not real life," said the actress, 34. "Sometimes I'll be like, 'Oh yeah, I forgot I'm married to you.' But it's been really nice having him here. He's very much a part of the family."

Meester said that her and Brody's 4½-year-old daughter Arlo Day had even told the couple while they were filming together, " 'You've been at work for so long.' "

"It's like, I've been here for one day," she said to ET. "She's like, 'Both of you guys can't work at the same time.' "

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.

So is Brody, 40, anything like his character on Single Parents? Meester says not quite.

"On the show, he's such a little dummy and it's very cute and he's very handsome," the Gossip Girl alum explained. "And in real life that's 98 percent not true. He's mostly, totally, like a grown-up."

Single Parents co-creator J.J. Philbin also shared with ET whether fans could see Meester and Brody reunite on screen in future episodes.

"We sure hope so. The way we ended season 2, Derek is even more a part of Angie's life (and even more of a thorn in Will's side)," she teased.

RELATED VIDEO: Adam Brody: The Best Thing About Working with My Wife Leighton Is ...

Philbin added, "So we imagine Derek being a huge part of season 3. Honestly, he has become such an important part of our ensemble, we can't imagine doing the show without him."

Meester and Brody met on the 2011 set of The Oranges. The couple tied the knot in early 2014, before going on to welcome daughter Arlo in August of the following year.

Last month, a pregnant Meester was photographed in Los Angeles, with her hands on the small of her back, wearing a gray T-shirt underneath a pair of long overalls.

While the spouses rarely discuss their daughter or even make event appearances together, they did both attend the premiere of Brody's film Ready or Not this past August.