The couple's fans and followers shared their messages of congratulations in the comments - including their former MAFS co-stars.
"So good to see you happy and that you have found your person," one of Lizzie's fans wrote.
One of Seb's fans chimed in with: "Such a beautiful couple!!! All the best guys."
Drew Brauer, who was a fellow MAFS intruder even joked: "Stop flexing @seb.guilhaus haha."
Seb and Lizzie, who first met when they partnered together on the reality show, enjoyed a fun-filled couple of days for their first weekend together, in person.
Lizzie shared a collage of photos that featured herself, Seb and some friends enjoying a night out as well as a video and photos of a coastal walk.
"These types of weekends is where you'll find my heart," the former bride captioned the post.
The couple originally planned to move in together in Sydney's Dee Why back in February, but the coronavirus pandemic put their plans on hold.
Former bride Lizzie added that long-distance took its toll on her and Seb's relationship, especially since they lived together during the experiment.
"It's definitely not easy, and we both thrive on physical touch. So that's a bit of a downer, because we can't do that right now," she told 9Entertainment in May.
Seb however added that their phone conversations have been the couple's "bread and butter".
"We've gotten closer, we've strengthened our bond, but we do still reach out for physical touch," he explained.
However, the pair aren't living together just yet as Seb revealed to that he was going to move in with a Sydney friend at first.