ET caught up with the Dancing With the Stars pros at the Children's Miracle Network Winter Wonderland Ball at Avalon nightclub in Hollywood, California, on Saturday, where the lovebirds couldn't stop gushing over the proposal and wedding plans.
Maksim, 35, told ET that he didn't reveal his plans to ask his 29-year-old girlfriend to marry him to anyone -- not even his mom or dad!
"I have a big circle of people that I've accumulated over the years that are now her friends and her family, and if you say just the closest few, [that would be] like 50 people, so I decided not to say anything to anybody. No mom, no dad," he said.
"I also wanted it to be kind of like a surprise for everybody. Everybody had an amazing moment that was very unforgettable," Maksim added. "And things like this need to be unforgettable. It needs to be special. But I told her I'm not planning anything else! I'm done."
There is one thing Maksim did get help with, however: Picking out Peta's gorgeous engagement ring.
"I worked with an incredible company [called] Cantamessa," he shared. "Their women's designs have been worn by royal families all over the world. I was Skyping with a group of Italian jewelry makers that are fourth or fifth generation! It was very easy in that sense. But as long as she liked it!"
Seeing as Peta can't stop flashing her sparkler in pics, we think it's safe to say Maks' choice was a success -- as was his now-fiancee's decision to say yes. "I couldn't see myself with anybody else," Peta chimed in. "He's the love of my life."
ET also chatted with the 29-year-old dancing pro during a DWTS tour rehearsal on Friday, where she revealed that the wedding will take place somewhere in Los Angeles and that she'll be the one making most of the decisions.
"I'm happy with that. I want to do it all," she told ET. "I'm cool with that. He can just sit there and turn up for the big day."
While they don't have a date set just yet, Peta confirmed that the ceremony will be "big!" Peta was on hand to co-host Saturday's event. "These
Children's Miracle Network hospitals are just the greatest thing in giving back
to kids and supporting and giving them free treatment," she said. "As long as we keep
giving, we'll keep saving lives."
ET also caught up with Maksim's brother, Val Chmerkovskiy, during the rehearsal, who seemed just as happy as the couple.
"I found out [Maks was proposing] a half an hour before he did that," he explained. "During intermission of our show, he started showing me the ring, and I bugged out."
"But honestly, it's long overdue," he continued. "We love Peta -- all jokes aside. I love her honestly with all my heart. She's been a part of the family for a long time. I'm just glad that now it's official."
This isn't the first time Val has expressed his excitement over Peta officially joining their family. He took to Instagram following the proposal to pen an adorably sweet message to his soon to be sister-in-law.