The guys in [artist id="3068464"]3OH!3[/artist] may be best buddies these days, but back in high school, well, they were bitter rivals. Even though they didn't really know each other.

See, as teenagers, Nat Motte and Sean Foreman attended neighboring schools -- Fairview High and Boulder High -- in the suburbs of Colorado ... two schools that, naturally, competed head-to-head in sports. And though the two didn't become friends (and subsequently form 3OH!3) until they met at the University of Colorado, they both remembered their high school rivalry and tell us all about it on the next episode of MTV's "When I Was 17."

Though, to hear them tell it, the so-called "rivalry" was actually a bit one-sided.

"We went to rival high schools," Motte said. "Junior year of high school, we beat the Fairview Knights 17-10 [in football], and we lost consecutively in all other sports afterwards. But we would still chant '17-10!' "

"We'd be beating them in basketball really hard, and they'd be chanting '17-10!' " Foreman chuckled.

And though the dynamic duo were divided by crosstown rivalries, they did share a similar interest in the bizarre ... which is what ultimately brought them together.

"My high school started a video-production program, so we'd air both newscasts and kinda cool, creative videos on public access TV, channel 54," Motte said.

"My mom thought I was a real weirdo, but I would watch public access television, and I remember seeing awesome videos that Nat made. I was like, 'Man, I want to meet that kid!' " Foreman added. "So I'm going to University of Colorado-Boulder, and I take a physics class, and I'm sitting in the class and I'm like, 'Oh my God, it's the guy from TV!' ... and that's how we met."

And things have been golden ever since.

"It was a bromance for the ages," Motte laughed.

"When I Was 17" -- this week featuring 3OH!3, Jordin Sparks And Jason Derulo -- airs Saturday at 11 a.m. on MTV.