Where does the time go? The Little Couple star Jen Arnold recently celebrated son Will’s 15th birthday with their family in a sweet Instagram video.

The TLC personality, 50, took to the social media platform with a clip of her teenage son standing in front of a birthday cake with lit candles on Monday, February 24. Jen’s husband, Bill Klein, could be heard behind the camera as the couple and Will’s sister, Zoey, 13, sang “Happy Birthday.” Will listened to the song with a huge smile on his face before he blew out the candles.

“Did you make a wish?” Jen asked her son in the clip.

In the caption, the mom of two added, “Another birthday in the books! I cannot believe you are 15 @willklein63! We are so so proud of the kind, fun loving, giving and smart young man you have become!”

Will was adopted by Jen and Bill, 50, from China in March 2013 after the couple, who both have skeletal dysplasia, struggled with infertility issues. Zoey was adopted from India a few months later. Like their parents, both Will and Zoey also have dwarfism.

“It wasn’t that we intended to, or tried to, adopt two children at one time,” Jen explained to The Wrap in December 2013. “It’s just how the stars aligned, really.”

Bill also opened up about their decision to adopt two children during a 2018 episode of The Little Couple.

“When Jennifer and I first got together, my selfish attitude was I wanted a kid that was genetically mine,” he admitted. “And then we talked about how many kids were out there that didn’t have a home, that needed love and support from a family and were relegated to a life of institutionalization. I think that I couldn’t have done any better a job through surrogacy, through the old-fashioned way or anything else.”

He continued, “When I saw Will’s picture, I fell in love immediately. When I saw Zoey’s picture, I fell in love immediately.”

Fans have since watched Will and Zoey grow up on The Little Couple, which aired its latest season in 2019, and on social media. However, their posts haven’t always been met with positive reactions. In 2023, Will was hit with backlash for dancing to Three 6 Mafia’s song “Half On a Sack,” which contained explicit lyrics, in a TikTok video with the Madagascar penguins.

“Hey parents out there, Jen here from The Little Couple. I thought I would just send a note out to everyone because, oh boy, I had one of those difficult digital media and kid weeks,” Jen said in an apology post after his video was taken down. “You may have seen that Will recently posted a dance trend on TikTok that unfortunately had a very explicit and foul language to the song that he chose.”

The pediatric physician added that she initially watched Will’s video with her sound off and “thought it was just another adorable video of Will dancing with some penguins.” Jen explained that Will understood “some” of the words in the song, but not the “implications of such language.”

“[Will] agreed to make better decisions because his social media is viewed more and that means he has a greater responsibility if he would like to use it,” she concluded. “I hope you all will give Will some grace on this as he is like so many kids out there, new to social media and still learning.”