It seems like only yesterday that The Little Couple brought their son Will home from China.

But, in this week’s episode of the hit TLC show, we see Bill Klein and Dr. Jen Arnold get ready to celebrate Will’s 5th birthday—and Popdust has video.

In true Little Couple style, Bill and Jen make it all about the family, enlisting daughter Zoey to help make Will’s big day super special.

The family re-decorates Will’s room with a transportation scheme—and, as Jen says, the arts and crafts foray is all about “controlled chaos.”

However, a little sibling rivalry flares up after Zoey takes a nap in her big brother’s bed!

Meanwhile, as Jen becomes even more swamped at work, SuperDad Bill steps in to take over the party organization—deciding on a Mad Scientist theme, complete with ‘scientists’ in lab coats who run colorful science experiments.

However, Jen is soon horrified to discover that she messed up on the one birthday planning task she was allocated—by sending out the party invites, with the wrong address on them!

Oh boy!

Will the party guests arrive in time to celebrate with Will?

Tune into The Little Couple tonight at 9/8c on TLC to find out!

In the meantime, watch sneak peek video below—and check out Popdust’s gallery of Will through the ages!