'The Little Couple' Engage In a Messy Cupcake-Decorating Battle for Zoey's Birthday

Dr. Jennifer Arnold and Bill Klein take their daughter and son to Georgetown Cupcake in Washington, D.C., to celebrate Zoey's fifth birthday

Confectioners in the making?

The Little Couple and their kids dive headfirst into frosting and sprinkles on an upcoming episode — and PEOPLE has an exclusive sneak peek.

Taking a trip to Washington D.C., Dr. Jennifer Arnold and Bill Klein help ring in daughter Zoey‘s 5th birthday at the famed Georgetown Cupcake with a little decorating contest.

With Klein and son Zach, 7, facing off against Arnold and the birthday girl, antics ensue — mostly on the boys’ end.

“If you were to take our two experiences — the boys vs. the girls — and put it into music terms, ours would be some heavy metal band and theirs would be like classical music,” Klein says. “They were methodical, they were paying attention to detail.”

Zach and Klein end up with icing all over their faces, while Zoey and mom complete the challenge mess-free.

Earlier this month, Arnold and Klein opened up to PEOPLE about how their children are adjusting after initial struggles following Zoey and Zach’s adoptions from India and China, respectively.

Zoey had difficulty bonding since she had been raised in an orphanage with no exposure to other little people. “She really wanted nothing to do with us,”Arnold revealed. Will also faced his own set of challenges. “He had hearing difficulties and has undergone surgeries,” Klein said.

Despite the obstacles, their children are now adjusted and happy: “They’re getting to an interesting age and finding their real passions.”

Shared Klein, “They’re really into artwork right now, their verbal skills continue to surprise me, and they’re doing so well in school. It’s fun to watch them grow.”

The Little Couple airs Tuesdays at 9 p.m. ET on TLC.