However, he's been keeping a very big secret this whole time: The musician, who also happens to be Mormon, is gay.
"I had my crushes on guys throughout high school, but it was never an overwhelming thing until my twenties," he told Rolling Stone magazine. "Then I'd be dating girls and in love with my straight friend, and it was the worst feeling in the world."
Though he's known for a long time that he was gay, it took Glenn some time to tell the people around him -- fearing a backlash from the Mormon community. As a result, in his early 20s, he only met men online and often found himself in "dangerous" situations.
"I found myself in situations that I normally wouldn't have ever put myself into, and that scared me," he explained. "It got dark."
Ultimately, Glenn's mother, Debbie, found him a therapist which helped him feel "like a human" again, he said.
She also insisted that his sexuality does not conflict with their family's religious teachings.
"He said, 'I don't want this to change your perspective with the church, I don't want it to tear apart our family,'" she told the magazine. "I just said to him, 'It won't change anything.'"