Brody and Kaitlynn first started dating in 2014, right before former stepsister Kim Kardashian's wedding to Kanye West.
Kait was famously not invited to the over-the-top nuptials, as their relationship was deemed too new at the time.
Season 3, Episode 19March 24, 2008Lauren and Whitney go to Paris, but the trip is marred for Lauren when she finds out Brody is seeing someone new.
Meanwhile, Spencer follows Heidi to Colorado to try to win her back.
Brody's mom, Linda Thompson, was even on hand for the festivities.
Season 3, Episode 26April 28, 2008Lauren, Lo and Audrina move into their new place together and throw a big housewarming party.
Later, Lauren and Lo get a blast from the past when Stephen Colletti visits.
The reality TV star popped the question to girlfriend of two years, Kaitlynn Carter, on Wednesday, while the two were on a tropical getaway to Indonesia.
"On May 4th 2016 I got engaged to my lover and best-friend," Brody, 32, captioned a photo of the duo on vacation.