\'Leaving Neverland\' director explains which part of his Michael Jackson doc disturbs him the most\, and why

• "Leaving Neverland" director Dan Reed opened up to Business Insider about the part of the movie that disturbs him the most.
• His 4-hour, two-part HBO documentary looks at two men who claim Michael Jackson sexually abused them when they were boys.

HBO's four-hour documentary, "Leaving Neverland" - which focuses on two men, Wade Robson and James Safechuck, who allege Michael Jackson sexually abused them when they were boys in the 1980s and 1990s - includes extremely graphic retellings by the men of their alleged sexual encounters with Jackson. (Michael Jackson denied molesting children during his life and was acquitted of child-molestation charges in 2005.)

Though director Dan Reed said it was hard to film the two talking about the sexual elements, what he found even more disturbing to lay out in the movie was what he called the "emotional manipulation" by Jackson. Robson and Safechuck say Jackson made them feel they were in a special relationship with him, only to feel throw aside later.

"He portrayed himself as this man who loved children and is a great benefactor of children, but he was the opposite," Reed told Business Insider. "He was a man who hurt children and did dreadful things to them."

Robson and Safechuck say Jackson would give them gifts, cash, talk on the phone with them (or in the case of Robson, fax), and pay the travel expenses for them and their families to visit him - whether it was at his California home, Neverland Ranch, or on tour somewhere in the world.

"Michael did a wedding ceremony with James," Reed said. "He felt he and Michael were going to be together forever. And Wade said he was 'my dad, my lover, and my mentor.' Jackson drew them into this fantasy that they were going to be a couple forever."

But, as we see at the conclusion of part one of "Leaving Neverland," that was not the case. The movie shows that around the time of Jackson's "Dangerous" album tour, two other kids became Jackson's favorites.

Robson and Safechuck were suddenly shut out from the person who was their everything.

"You're no longer special," Safechuck says in the movie about how he felt after realizing Jackson was focused on someone else.

Read more: Inside the making of the 4-hour HBO Michael Jackson documentary, "Leaving Neverland," which contains harrowing allegations of child sexual abuse

Reed said that's the part of the movie for him that's the toughest to watch: when Jackson shuts out the boys.

"To do that to a little child that you seduced, whose world you completely turned upside down; Jackson played God with these kids and then he disappeared," he said. "He left their lives in ruins and that's what I think we're holding him to account for."

Part 2 of "Leaving Neverland" airs on HBO on Monday. Both parts are available now on HBO GO/NOW.