In excerpts from his upcoming memoir "The First Time," the reality TV star wrote about how he was bullied in grade school about his appearance, before rumors about his sexuality began to take over in high school.
"I was called fatso, four eyes and four lips, because I used to lick my lips, so I would constantly have a red ring around them," Underwood said, via PEOPLE. "I was a little heavy, and that, combined with being socially awkward, led to a really hard time. I didn't believe in myself. And I was super insecure."
Underwood, who famously kept his virginity intact until he led the 23rd season of the ABC dating show, says he began wondering whether he was gay before the taunts began in high school. According to the book, he even searched "Am I gay?" online when he was in grade school.
"I didn't know who I was. And I come from an athletic family, so it was always, 'Move on, you're good,'" he said. "So that threw me off. In high school, when I was struggling with my sexuality, I'm not going to talk to my parents about it. So I internalized it."
"It was one of those things where you hear something so often, you start believing it," he said of the homophobic bullying. "I thought, maybe I am gay. The captain of the football team should be having sex and drinking, right? But I wasn't."
He added that "even while my season [of The Bachelor] was airing, I battled the gay [rumors]." As viewers questioned his sexuality, he said it was nothing new, adding, "I've been there, done that now."
While they still aren't engaged, Underwood and winner Cassie Randolph are still together. He's actually been holed up with her family while battling the coronavirus -- see more about that here.