As festival season gears up into 5th Gear, a lot more than just DJs and producers will be making appearances.

Music festivals are a veritable Petri dish of celebrities and A-Listers who go out to have a good time, and that includes athletes, as well. One of the biggest celebrity athletes of the year is New England Patriots’ tight end Robert Gronkowski, who played an integral role in the Patriots winning the Super Bowl last month. Festival goers had the opportunity to witness a once-in-a-lifetime sight yesterday as “Gronk” hopped up on stage to join 3LAU, who was sporting a Patriots jersey, and proceeded to shake what his momma gave him. The twerk spectacle was well received by those who knew who they were watching; even for those who were completely unaware, watching a 6′ 6″, 265 lbs white man in a bright neon yellow ensemble is a sight in and of itself.

Watch the (too perfectly looped) Vine below from Ultra’s Twitter.