Smash Mouth singer Steve Harwell needed to watch his mouth during his band's appearance at the 2015 Taste of Fort Collins festival: In response to fans throwing bread onto the stage, Harwell launched into an expletive-laden tirade, during which he threatened to attack fans. Check out the NSFW video of the incident below:

"You throw one more piece of s--- on f---ing stage, I'm going to come find your a--, I'm gonna beat your a-- whoever the f--- you are out there, okay?," he said, before tempting the fan to join him on stage while calling him a "p---- punk b----."

He continued, "You're ruining the show for thousands of people right now, because I'm going to walk off stage, and guess what? You're paying for it, motherf---er, okay? Come on, someone throw one more thing at me right now."

TRI 102.5's Dave Jensen was backstage and recounted the scene in a blog post, writing:

Then…. there he was. He scared the crap out of me. The guy is big, and he was pissed. I stood there, waiting to see what he was going to do. I think that maybe I thought I could help him. Then it was clear that he didn’t need my help at all. This was his show, and his meltdown. I was ‘O.K. I’m getting out of here.’ I turned and headed back off stage.

He goes into his tantrum. Backstage, they are FREAKING out! ‘What’s he doing??’ ‘What are we going to do?’ ‘Somebody get up there a chill him out!’. Then that guy with the beard goes out there and tries to keep him from doing something he’ll regret- like punching a concert-goer.

Harwell eventually calmed down, returned to the stage, finished performing "All Star" and the show was over. Check out the full behind-the-scenes blog post here, via TRI 102.5.