Katy Perry offered to buy a round of drinks for her fans at her concert over the weekend

Speaking to 'Entertainment Tonight', the 33-year-old singer said: "Last night I was doing a show in Santa Barbara for the mudslide relief in Montecito, and 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.

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

Katy still hasn't received the bill from the bar but she's expecting it to be pricey.

She said: "I think they're still crunching the numbers."

This isn't the first sweet gesture Katy has done recently as she reached out to her long-term enemy Taylor Swift last month in a bid to bury the hatchet once and for all.

A source said at the time: "Katy planned a very personal, sweet apology and took time to write a kind note in hopes Taylor would see how much she cared about putting this behind them.

"Katy told friends if Taylor didn't accept this apology, she would keep trying because she is done holding on to the past and wants to be part of the change in today's society.

"She wants to set a good example for women, so she planned to never give up, if that is what it took. Katy hopes they finally can be supportive of each other's music and maybe one day soon even hang out together again.

"Katy realises they need to take it one day at a time, but that this is a great start."