The 33-year-old told the gossip blogger: "The thing with that is, this bullying that you did for so long to so many young girls, I find it hard to let go. I really do, it's not just about the body shaming or outing people who are gay before they're out of the closet, all of that stuff, I just can't really accept the apology entirely on behalf of how I truly feel. I think really where I think the divide between us is I don't sit well with people who purposefully harm other people."
Perez responded, "If I could go back in time -- and I say this on my kid's life, I swear -- if I could go back in time and do things differently I would" but Mischa quickly fired back "Would you, would you really?"
From there the argument kicks into overdrive!
See the full thing in the above clip.
The Hills: New Beginnings airs Tuesdays on MTV.