The Chainsmokers wanted to rock an event for Arizona State University … pulling up to play a frat party — but, Johnny Law showed up to douse that idea really quick.

Alex Pall and Drew Taggart pulled up to Tempe, Arizona Friday ahead of Breakaway Festival — a popular EDM festival — that took place in Phoenix over the weekend.

The duo went to excite the crowd … and, they ended up having a face-to-face meeting with some police officers — who weren’t happy about the massive event one bit.

Congresswoman Nancy Mace says she was harassed at a store, sharing a clip of the interaction … though many online are split about who’s in the wrong here.

The representative from South Carolina shared an interaction she says went down at a makeup store this weekend … filming a dude after it seems he asked her if she planned to have any other town halls this year like she did last year.

While the man seems to be asking with what might be a bit of snark and amusement in his voice — Congresswoman Mace loses it … repeatedly saying this man is harassing her and telling him he could’ve gone to a dozen town halls last year.

He responds by asking if she think that’s the only thing that matters to him, and she tells him she thinks everything about him has to do with gay marriage.

The convo devolves from there … with Congresswoman Mace telling him to get out of her face despite the distance between them before saying “f*** you” to the guy while he’s walking away. He responds by calling her a “nasty b****.”

Mace called the man she spoke to a “unhinged lunatic” in her X caption — roasting him for wearing short shorts and shopping in a makeup store … and claiming he “got in her face” which is why she went off.

She adds she’s not backing down and plans to “hold the line 24 hours a day, 7 days a week, 365 days a year.”

Mace is a Republican — who told us last year she wanted then-President Joe Biden removed from office via the 25th amendment — so, a few on the right are backing her here.

However, a whole bunch of people online think — based solely on the video — that Rep. Mace was completely out of line here … calling her out for attacking this dude instead of trying to have a civil conversation with him.

You know how we like to settle debates here … vote below!!!

Justin Bieber‘s revealing what music gets him grooving … his own stuff — ’cause he was vibing to a couple of his well-known tracks at an invite-only event near Coachella Friday night.

As we told you … the singer-songwriter attended Friday Nights in the Desert — a private party in Thermal, California, not far from where Coachella takes place.

While we were told he performed at the event, we’ve now obtained video of Bieber at the show … and, though it doesn’t appear to be an all-out performance, JB’s clearly listening to one of his own tracks, bobbing his head to “What Do You Mean?”

JB also enjoyed “Maria I’m Drunk” — his collab with Travis Scott and Young Thug — as well as Scott’s “I KNOW ?”

ICYMI … Bieber, his wife Hailey, Megan Thee Stallion, Ty Dolla $ign, Don Toliver, Shaboozey, Chase B and many more stars attended the event — organized by Tao Group Hospitality, REVOLVE and Palm Tree Club.

It’s one of the many trips Bieber has made to the desert this month … ’cause he’s been hanging around Coachella — throwing a private event in the area during Coachella’s first weekend.