But that's not a bad thing for the two Mammoth, Calif., skiers.
Whether it's on the football field at Mammoth High School, where Teller, 29, coached Wallasch, 18, or at Teller's summer skicross camps, which Wallasch attended, the duo is always competing.
"He made me want to put on the pads and go and whack him a couple times," Teller said of coaching the versatile athlete.
On Friday, they were battling again, this time with a national championship on the line in the skicross finals at the U.S. Grand Prix at Canyons.
Moments after watching Madeline Riffel (who is also coached by Teller) win the women's national championship (finishing second overall to France's Ophelie David), Wallasch was chasing his idol down Doc's Run.
Teller got out to an early lead, something he had been doing all weekend.
"It's always easiest if you can get out in front and stay in front," he said of the narrow Canyons' course.
But Wallasch wouldn't go away, staying right behind Teller for the entire race, waiting for an opportunity to get around his coach. That opportunity never presented itself, however, and Teller held on to claim the national championship.
"I would have liked to beat him," Wallasch said. "But it's cool to finish behind him too. I've known him forever and he's an awesome guy. It's a dream come true and I hope I can continue to keep up with him."
Teller, who crashed during last year's Grand Prix at Canyons after crashing in the 2012 X Games, said this year's victory was very redeeming.
"It was kind of a disappointing month for me," he said of February 2012. "I had three crashes in a row and I was getting pretty sick of it."
Now Teller, who turns 30 on March 9, is skiing well heading into the 2013 Freestyle World Championships in Oslo, Norway. Despite being one of the older competitors, Teller said he's "still 18 at heart."
On the women's side, Riffel managed to avoid the worst of a three-skier crash in the women's race, staying mostly clear of danger to claim her second-place finish.
"I didn't think I had a shot," she said. "I thought I was down and just had to finish the race. Then I went past everybody and saw a ski on the ground and thought, 'I'm in second; I've got to finish this thing.'"
David cruised to an easy victory to win the Grand Prix, but the 18-year-old Riffel was the first American across the line, earning her first skicross podium finish and first national championship.
"She's come a long way in the last two years," Teller said. "She's starting to get a lot more comfortable with her jumps."
Langely McNeal, the defending national champion, was caught up in the crash in the women's final and finished third.
"I'd be lying if I said I wasn't a little bit crushed," she said. "But I'm glad to see Maddie get it. She's a great girl."