Inside Mark Salling's Time on 'Glee' — and His 'Stormy' Relationship with Naya Rivera

While his character on Glee is known as a man of few words, Brad Ellis (known as “Brad the piano player” to fans) is speaking out about the recent death of his former cast mate, Mark Salling.

The late actor died in an apparent suicide at the age of 35 on Tuesday, just one month before he was to be sentenced to prison for possession of child pornography. Ellis, who also worked behind the scenes on Glee‘s musical production, tells PEOPLE exclusively that he knew Salling before his downfall as “personable and affable” with a “very light quality to him sometimes.”

“It has been a few years for darkness to take hold,” Ellis explains. “It occurred to me that part of his problem might have been that very lightness that I’m talking about, that certain kind of humor that he liked that sort of implied sometimes he didn’t see other people as complete. When a bunch of privilege gets dumped on a person when they’re young, there can be an aspect to which other people’s lives that don’t directly connect to theirs aren’t entirely real. Part of the problem might have been him not understanding that there were real victims involved in what he was collecting.”

During Salling’s days playing bad boy Noah “Puck” Puckerman on Glee, Ellis can recall two instances where he saw a darker side to the actor — one of which involved Salling’s relationship with his ex-girlfriend and costar at the time, Naya Rivera, whom he dated for three years while filming the show.

“There was a bit of a stormy nature to his relationship with Naya but never in a way that became unprofessional,” Ellis says. “That certainly wasn’t all lightness and happiness.”

Rivera has said Salling dumped her in 2010 at the request of his publicist, who allegedly said she wasn’t good for his image. In her 2016 memoir, Sorry Not Sorry, Rivera gave some insight into her mindset after learning of Salling’s child pornography charges and said, “I can’t say I was totally shocked, but still – WTF?”

“When Mark dumped me, I thought it was the worst thing ever, but can you imagine if that didn’t happen? And I was laying there in bed when the battering ram came through the door?” Rivera wrote. “I think everyone should have that one relationship where you look back and ask yourself, ‘What the hell was I thinking?’ You’ll learn something and you won’t regret it. Unless, of course, that relationship was with someone who had a sizable stash of child porn on his computer. Then, by all means, regret everything.”

Rivera has not commented on Salling’s death.

Ellis also described an alleged run-in with Glee’s network, Fox, over an album he made between two of the seasons. Salling didn’t get permission to make and release an album as he requested, so he did it anyway, and his contract was held up as a result, Ellis claims.

“He thought he was fired,” Ellis says. “As it happens, he was something very useful for the show. What they realized was Mark, as an actor, had exactly the right heavyweight quality. It was heavy enough for him to be somewhat threatening in the world of Glee. So they brought him back.”

He continues: “The first day he was back, I remember he was very chastened and he thought, ‘I went up against the big dog, and I’m not going to do that again.’ Which is not something young people who have suddenly been made stars say a lot. The darkest thing was that he didn’t like how that whole thing went down, [but] interestingly enough he took responsibility for it.”

With the drama came a lot of good times on set, though — especially Salling’s relationship with costar Cory Monteith, who died at the age of 31 in 2013 from an accidental mixture of heroin and alcohol.

“He and Cory, they were kind of ringleaders for humor when they were together when everyone was sitting in our little canvas back chairs waiting for the next time we were going to shoot something,” Ellis says. “[Salling] may have been instrumental in the best prank.”

The prank Ellis describes involved getting the props team on board to put a gigantic, 3D scratch on the side of Monteith’s car that was parked next to his girlfriend Lea Michele’s to make it look like she was the one who did it.

“Cory is taking his look like, ‘It’s only property, you didn’t mean to destroy it,'” Ellis says. “And Lea’s like, ‘I swear it wasn’t there when I parked! I would’ve heard something.’ No blame was ever completely assigned, but I think Mark might have been the ring leader of that and it was pretty brilliant, actually.”

While Monteith’s death had a deep impact on everyone involved on the show, Ellis says Salling was “not in a good relationship and support system” at the time to handle it.

“So much was happening in his life to remind him real things happen and real things are bad,” he says. “It’s just taking away from a fantasy life which is television and a limo picking you up to take you to an awards ceremony.”

As for how the cast dealt with fame after skyrocketing to success with the show, Ellis says they were “their own best support system” and “put up with a lot.”

“In real world terms, they were well paid but [not] in the terms of how much work, how much extra time they put in rehearsing choreography and so forth, the rigors of the recording schedule, the intensity of filming,” Ellis says. “I heard it said from a lot of people who would know that they were the hardest working, worst paid cast in Hollywood history.”

Despite the taxing schedule, Ellis says more often than not, Salling was “keeping it light, keeping it going, and putting his heart into it.”

“The side that he chose to show us, me and those that weren’t that close to him on set, was affable and sweet and patient and hardworking,” he says. “Very rarely would there be a glimpse of anything that could possibly be as dark as what led to the end of his life.”

Though Ellis doesn’t excuse Salling from his actions and crimes, he says he’s a “big believer in redemption.”

“I think there’s this alternate universe where he takes his punishment, accepts it deeply and goes on to contribute something to the world,” he says. “Everyone is one inch away from finding their purpose, even those who have made the worst possible mistakes.”

If you or someone you know is considering suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).