"We're just going back to being boyfriend and girlfriend," said Montag in the December 31 issue of Us Weekly.
The Hills' pre-taped third-season finale broadcast concluded with Montag moving out of her apartment with Pratt and traveling to her home state of Colorado to be with her family.
Montag and Pratt had been bickering with each other in the episodes leading up to the finale -- with most of their arguments centered around planning for their wedding -- as he constantly pestered her about wanting to elope or get hitched overseas while she wanted a more traditional wedding.
"I need to accept that Heidi wants her princess wedding and that she is the boss," Pratt told Us, adding there's a part of him that's glad they're just dating again because that's "when our relationship was flawless."
As for the engagement ring -- which Montag arrived at The Hills live after-party broadcast without -- she's decided to turn it into a pendant.
"It wasn't my dream ring," Montag told Us. "I don't like what it represents. I might sell it."
The never-ending feud between Montag and herThe Hills co-star Lauren "L.C." Conrad originated with the former Laguna Beach queen not approving of Montag's choice of Pratt as a beau. Montag told Us it "would be really sad" if Conrad found humor in her and Pratt's relationship troubles.
Back in September, a "friend" of Montag and Pratt toldOK! Weekly that The Hills couple everyone loves to hate was "going to stage a huge breakup, and Heidi is going to pack up all her stuff and move out of their apartment" -- a virtual blow-by-blow account of exactly what unfolded during the third-season finale.
Of course, the "friend" also claimed that Montag and Pratt would have a romantic "reunion" once they sold their story to the press.