The Hills star Spencer Pratt is opening up about the years-long beef he's had with his younger sister, Stephanie, ahead of The Hills: New Beginnings premiere on MTV. It's been nine years since the original series last aired, and from the looks of it, Spencer hasn't forgiven or forgotten any of it.

Viewers first met Spencer on the original Hills, a Laguna Beach spinoff airing from 2006-2010, that followed the lives of former Laguna Beach star Lauren Conrad and her BFF, Heidi Montag. Heidi began dating Spencer, and the two were the center of much controversy on the show, with Spencer being the reason behind Heidi and Conrad's relationship falling apart. Spencer managed to make a lot of enemies during that time, one being his own sister Stephanie Pratt. Since she was on season 3 of the original The Hills, she took the side of Lauren instead of her brother. Their on-screen reality TV drama transferred to their personal lives and they went years without speaking. Stephanie even has said the situation caused her to be hospitalized due to stress a few times and that "nothing" could be done to salvage their relationship.

Related: 20 Wild Details Behind The Making Of The Hills

When told by E! News' Justin Sylvester that he seemed like he "can hold a grudge," Spencer replied, "Yeah, my burn diary is out."  The reality TV star and crystal fanatic went on to say that he has a "hit list" of people he has beef with and reminded the host that the first episode of the season will be aptly titled "I don't hold grudges. JK." When pressed about who was on his "hit list," he said, "Everyone. No one was safe." However, his sibling, shockingly, isn't at the top. "I have no beef with any family member," Spencer said, adding, "It's totally one-sided." When asked if Stephanie was making up their fight to muster more interest in the reboot, he replied coyly, "I think Stephanie is a great asset to the show." Spencer, usually an open book, was being tight-lipped in light of Monday night's premiere.

Brody Jenner and Kaitlynn Carrter

However, just a moment later he revealed a pretty major plot point of this upcoming season: that cast member Brody Jenner is potentially cheating on his wife, Kaitlynn Carter, who has also joined the reboot. He said, "Brody Jenner is still the biggest mack on The Hills," and was then asked if Brody is getting more girls than co-star Brandon Lee, to which Spencer replied: "Yes. Currently." However, Spencer quickly corrected himself, saying, "Oh wait, no, he's married.

In addition to potential scandals playing out on The Hills: New Beginnings, the show will shed some light on Heidi and Spencer's personal lives as parents and as small business owners of a crystal company called Pratt Daddy Crystals. On the first episode, Stephanie moved back from London to Los Angeles to repair the relationship between her and Spencer. It seemed like things are getting on the right track with them as Heidi and Spencer decided to go to Stephanie's welcome home party. Now, the bigger question on audiences minds is what is going to happen this season on The Hills: New Beginnings with the cheating scandal that Spencer hinted about Brody and his new wife Kaitlynn. Could it be that Spencer actually slipped up and spilled inside information or was he just adding mystery to the show?

Next: Everything That's Confirmed About The Hills Reboot 'New Beginnings'

New episodes of Hills: New Beginnings air Mondays at 10pm EST on MTV.

Source: E!