'Dancing with the Stars' pro Louis van Amstel thankful for fatherhood with his two adoptive sons

LOS ANGELES (KABC) -- On this Thanksgiving, "Dancing with the Stars" pro Louis van Amstel is giving thanks for his two adopted sons.

Yes, he has three world championship dance titles and a successful fitness business but being a father has changed Louis' life.

He recalled a story that happened to his son one day at school.

"The substitute teacher asked the kids, 'So what are you thankful for this Thanksgiving?' And it was Daniel's turn. And he said, 'To finally be adopted by my two dads.' The moment he spoke that word, 'dads,' she didn't miss a beat and said, 'Why would you be thankful for that?'

When that happened a couple of years ago, the famous dancer didn't dance around his feelings for what the substitute teacher had said. He went on social media and said his son had been bullied. The story was picked up around the world and that teacher lost her job.

Louis van Amstel got his job on "Dancing With The Stars" on season one.

Now at 50, he returned for season 31, the show's oldest pro ever.

"Yes!" he said, "And I am proud of it!"

When van Amstel danced with Lisa Rinna in season two, he started holding dance fitness classes in a studio in Sherman Oaks.

By the time he danced with Kelly Osbourne, he decided he could turn his classes into a company. He named it La Blast.

"And we're now in 10 countries," he said. "And we have 4 - 5,000 people certified to teach La Blast. And we have an on-demand program that is growing. Thank you 'Dancing with the Stars.'"

After van Amstel married his husband, Josh, they decided to adopt an older child through foster care. They soon had two sons, now 13 and 14. Van Amstel is outspoken about finding permanent families for children in this country in need of loving families.

"And because it's state adoption, you actually get support from the federal government until the kids are 18 - Medicaid - you get support, so much support," van Amstel said. "And it took us, I kid you not, nine months from the start to finish. So we felt pregnant!"

When it comes to his sons, he relishes that moment every father waits to hear.

"The first time your son, your adopted son, says 'dad.' When you have a child, you know, from birth, you're waiting for that first word. That's the word. We missed those 10 years. So for them to say 'dad,' it's everything," he said.