Singer Pink says Christina Aguilera and she have gone through lots of ups and down as friends -- so much so that they almost got physical with each other.

Pink spoke about her friendship Aguilera on TV show "Watch What Happens Live with Andy Cohen" on Thursday, reports people.com.

"We were super young and super new at the whole thing, and I think I'm an alpha, and she's an alpha," Pink said.

"I'm used to taking my altercations physical and she's used to having them verbal. We're just very different, we're very different. And we were very young and new. You have to learn -- women have to learn how to support each other. It's not taught to each other in the playground," she added.

When host Andy Cohen asked if Pink had attempted to make an argument into a physical fight, she said: "Actually, she (Aguilera) swung at me in a club. Hilarious! I was like, ‘What's happening right now? What's happening?'"

The two signers clashed when they recorded the track "Lady marmalade".