Katy Perry's on-stage gift to fans hilariously backfires

Singer Katy Perry instantly regretted treating her audience to a beer. Photo / Getty Images

Katy Perry made a generous offer to fans at a recent concert - but it blew up in her face within seconds.

The Teenage Dream singer was performing a Witness: Coming Home benefit show in her hometown of Santa Barbara, with proceeds going to benefit the region after devastating recent natural disasters.

Apparently on a whim, Perry decided to extend the charitable nature of the event even further by shouting everyone present a drink.

"I'm just going to 'executive decision' this: I'd like for all the beers to be on me tonight. Make sure everyone gets a drink on me, all the beers," she announced mid-concert.

"Look at this guy - he's just left his seat! He's like, I'm out, I'm going," she said, pointing to one gentleman who was apparently super-keen to take her up on the offer.

Within seconds, he was joined by more - and more, and more.

"But hold on... you guys, it's a good show. Don't leave. Everyone's leaving..." Perry pleaded.

In fan-filmed footage of the incident posted to Twitter, dozens of concertgoers can indeed be seen heading for the exits to get their free drinks:

Perry was good natured about the mass exodus though, telling Entertainment Tonight the day after the show that she'd noticed it was mainly men who'd been dragged along by partners who headed to the bar.

"There's a lot of guys who are there 'cause I think they want to be, but I know that they're usually there to support their wives or girlfriends or kids," Perry said.

"I'm like, 'You know what? I'm opening up the bar and buying everyone a beer!' So all the men — even my own sister's husband — left and they all came back double-fisting. It was amazing."

Speaking at the same event, Perry was her usual candid self when asked her opinions of last weekend's royal wedding.

She said she thought Meghan Markle's controversial wedding needed "one more fitting".

She even compared Meghan's look unfavourably to Kate Middleton's dress during her wedding to Prince William in 2011.

"Kate won!" Perry said. "Kate won! I'm sorry! I'm never not going to tell the truth! One more fitting! But I love you!"