"It's pretty surreal seeing myself as a child, wanting love and not getting it the way I wanted it and then looking at Brandi and realizing I was doing exactly what I got," he says in the preview clip. "It was real, I felt his pain, I felt my daughter's pain."
"What would you say to a younger Brandi?" Dr. V asks him, as he addresses the girl playing the role of his daughter. "You wanted a lot more than I gave you," he responds, "and I really apologize for that."
"My heart's broken," he says as he then sits back down next to his real daughter.
In a confessional, Guy explains that the drill "actually helped unlock what I've been denying Brandi and that was the affection and love I should have given her and I didn't."
While things may be on the mend between the Glanvilles, there's more drama to come elsewhere in the episode as Amber Portwood's ex Matt Baier "breaks down when he exposes a shocking event from his past" and Renee Graziano "goes ballistic" when she imagines a future without her sister.
"Marriage Boot Camp: Reality Stars Family Edition" airs Fridays on WE tv.