Andi, 34, posted her first photo with Blaine in which the couple was sharing a kiss on New Year's Eve at The Breakers Palm Beach on Friday.
"By far my favorite thing from 2021," Andi captioned the sweet image.
And then on New Year's Day, Andi uploaded a photo of the pair posing side by side in formal attire outside of the swanky hotel. Andi looked beautiful in a metallic silver gown while Blaine sported a tuxedo.
"Cheers to a year filled with love and sparkles. 2022... I have a feeling you might very well be the best one yet! Happy New Year," Andi wrote alongside her post.
According to a source, Blaine is a man from Andi's past.
The lovebirds reportedly "met each other years ago during college through a mutual friend, who went to school with Blaine in South Carolina," according to E! News.
"They both happened to be in Italy at the same time this past summer and reconnected after 15 years," the source added. "They have been together ever since!"
Andi and Blaine's romance is reportedly "the fairy tale Andi always dreamt of," with the source adding, "She has never been happier before in her life."
Blaine, who works in commercial real estate and played baseball in college, currently resides in South Carolina while Andi lives in Los Angeles, CA, but Us Weekly reported the couple has been making a long-distance relationship work.
Andi has written two tell-all memoirs, It's Not Okay: Turning Heartbreak into Happily Never After as well as Single State of Mind, the first of which bashes Josh and how he had treated her during their short-lived relationship.
Andi had accused Josh of being verbally abusive, temperamental and controlling in her book -- which Josh in turn called "fiction."
"I was disgusted with myself for what I put up with. I was a strong, independent woman and I allowed [Josh] to be [emotionally abusive]. Now, I know I don't want someone jealous or controlling. I know what won't make me happy in [the future]," Andi told People in 2016.
"We all have red flags in our relationships that we don't see. Looking back and seeing those red flags was very cathartic for me. I realized our relationship wasn't the highlight of my life like I thought it was. So I took it off the pedestal and realized all was not lost."
Josh went on to appear Bachelor in Paradise's third season in Summer 2016. He got engaged to Amanda Stanton during the BIP finale, but she later voiced similar unflattering comments about Josh after their December 2016 breakup.
Amanda told E! News in 2017 that Josh had a bad temper and was "extremely controlling." For instance, he allegedly never liked it when she partied or hung out with her girlfriends.
But in April of that year, Josh fired back during an interview with E! News and demanded that Amanda "stop lying" about him and "stop speaking to the press" about their relationship.
Josh later starred on E!'s Famously Single reality series.
In January 2021, Andi admitted she would have made very different choices on The Bachelorette if she could go back and do it all over again.
"Honestly, if I had to pick a different person from my season it would not have been Nick, who was second. It would have been Chris Soules, who was third," Andi said on the Dax Holt and Adam Glyn's "Hollywood Raw" podcast in January 2021, according to Us.
"He was my buddy, my friend. I really liked Nick and Josh... Chris was like my safety blanket. He was the guy I could go on a date with and I knew that we would have a good time. There wasn't a ton of pressure."
Andi, who was single at the time, said she wouldn't want to do the show again, even though she really enjoyed starring on The Bachelorette.