Partner workouts are often one of the best ways to force yourself into an uncomfortable state. Another example of this type of discomfort is--you guessed it-- interval workouts. So think of each round as an interval. You get to rest while your partner works, which means you want to take full advantage of said rest so that you get your next round done as quickly and to the full efficacy you can achieve. So find your buddy, put your head down, and go. Have some fun with this one. And tell your legs you're sorry.