"She said yes!! I want to give a big thank you to all our family, friends and supporters for all the love and congratulations," Victor, 27, tweeted along with a photo of the couple.
The fitness enthusiast also noted, "Additionally none of this would have been possible without @cbs_bigbrother. Lastly big thanks to @sarahojewelry for the beautiful & custom ring!"
As for Nicole, the 26-year-old nurse wrote on Instagram, "So blessed. So loved. So grateful. So happy. #ohmygosh."
Nicole, the winner of BB18, and Victor, best remembered for being a competition beast that season, confirmed on Twitter in September 2017 they're dating after just establishing a friendship in Summer 2016 inside the Big Brother house.
During Sunday night's Big Brother broadcast, Nicole entered the house thinking she was going to host "a luxury competition," but instead, her boyfriend Victor had set up a sweet marriage proposal for her.
Victor appeared on the big television screen in the living room -- while Season 20's houseguests were all piled into a different room -- and a montage began to play, featuring footage from Victor and Nicole's time together in the Big Brother house two years prior.
"I knew when we had that first kiss in New York that I was in love with you. Nicole, I will be very honest with you. The last place I ever thought I'd be living is Ubly, Michigan, and now I live in Ubly, Michigan," Victor said with a laugh.
"Wherever you are is where I belong, and now I can't imagine being anywhere else."
Nicole broke out into a series of sobs and sighs while listening to Victor's heartfelt speech and profession of love.
"Nicole, you are the most beautiful, most kind, most giving and generous person that I know," he said. "You are my soul mate, you are my lover, you are my best friend... Even though I didn't win the money, I walked out of Big Brother with the biggest prize of all, and that's you."
Victor then surprised Nicole in person with a totally new look. Not only did he chop off his long hair, but he was also clean shaven.
Nicole kept repeating, "Oh my gosh" because she was stunned by her boyfriend's appearance and surprise proposal.