The Bachelor Nation star recounted her time studying alongside the pop superstar when they were both students studying theater at NYU's Tisch School of the Arts during the early aughts. Though Waddell considers herself to be somewhat of a Little Monster, she was admittedly "not a fan" of Gaga—born Stefani Germanotta—back when they were on the edge of glory in college.
"Stefani used to, during lunch, play on the piano," Waddell recalled on the Nov. 6 episode of the Trading Secrets podcast. "You would eat lunch in a dance studio and there was a piano, and she would sit at the piano every single day and just play and sing Wicked at the top of her lungs every day. And we were all just trying to eat lunch. It was break time, and we were all forced to listen to her."
The 38-year-old continued, "And yes, was she good? Of course! She was great, but I just wanted to eat my sandwich. And so, I used to just eat in the hallway because she was driving me crazy."
While Waddell didn't think Gaga, now 37, was exceptionally more talented than the rest of students in their elite art program, which accepted around 60 people per year, she noted that the future Grammy winner did set herself apart in the fashion department even back then.
"She would wear these really tight leotards," Waddell remembered, "and her boobs were just like coming out. She's so ridiculous."
The Bachelor alum added that Gaga would especially make heads turn when she performed her own material, as opposed to following their musical theater training from the Collaborative Arts Project 21 (CAP21) program. "When she played at the NYU talent show, she was singing her own stuff and I was like, 'You can't argue, that girl is really good,'" Waddell explained. "She was good at everything, but she was better at her own stuff. She was down at the piano, wailing her own tunes."
Ultimately, Gaga dropped out of the program to pursue her own musical career, a choice that Waddell—who also chose not to finish her studies at Tisch—applauds in hindsight.
"I don't know what she did, but she's a genius," she told host Jason Tartick. "I wasn't a fan of her at that moment, but I was not my best at that moment either. We both dropped out of the program because we didn't love the program, and I'm sure she was just as unhappy in it as I was or she would have stayed."
Waddell has since found her way into the music industry as well. These days, the Bachelor in Paradise winner—who shares kids Isabella "Bella" Evelyn, 5, and Charles "Charlie" Wolfe, 3, with ex Evan Bass—is pursuing a career as a pop-country singer.
"This is not the ideal time to put music out, but I think the ideal time for me is now," she shared. "I like telling people you can do it whenever."
E! News has reached out to Gaga's rep for comment but hasn't heard back.
In the meantime, keep reading to check out famous celebrity feuds from over the years...