AceShowbiz -

Wedding bells are on the way for Kym Johnson and Robert Herjavec. The female "Dancing with the Stars" pro-dancer and her "Shark Tank" beau broke the engagement news on Twitter. He wrote, "I asked .... @kym_johnson," to which she replied, "I said yes."

Herjavec, 53, popped the big question with a 6.5-carat ring. "I still can't believe that a year after walking into a dance studio of all places, my life has changed this much," he tells PEOPLE. "Kym is an incredible woman and I'm just so excited for what the future brings for us."

After the proposal, the couple was toasted by their family and friends. "To celebrate tonight with our family and friends, and my mom who flew in from Australia, wow - I'm just overwhelmed and so happy," the bride-to-be says. "He's a wonderful man and I'm so lucky."

Johnson, 39, started dating Herjavec after they were paired up on "DWTS" Season 20 last year. "We were friends first," she explained. "We got to know each other on a friendship level. That developed into something else. We're both each other's number one fans, and have respect for each other."

Robert Herjavec was previously married to Diane Plese. They divorced after 25 years of marriage. They share two daughters and a son.