Demi Lovato knows how to handle herself!

The 22-year-old "Heart Attack" singer had some words for Ashley McMullen, a tattoo artist who called out Lovato for acting like a drunken slob, urinating on her toilet seat and not paying for her infamous "vagina tattoo."

The confrontation began after Lovato shared a photo of a giant rose covering up the lips tattooed on her forearm. She captioned the pic, "Bye bye and hello... Thank you SO MUCH to my brother @GEESPOTAT2... It looks beaaauutiful and I LOVE it!! #RIPvaginatattoo #kidsdontdodrugs.

In a Tweet, that has since been deleted, the former Disney darling responded to McMullen by apologizing for her unprofessional behavior and for referring to her lips tattoo as a vagina.

"Dear Ashley McMullen, I wasn't going to acknowledge your bitter Instagram comments but since your side of the story has picked up some headlines, I would like to share my thoughts and send you a proper apology," Lovato wrote via Twitlonger (via People). "First, I would like to say I'm really sorry I don't remember you or getting tattooed by you, but as you know I was f--ked up and sometimes people act like '#turds' when they're loaded. Second, I apologize for my '#peepeetoiletseat'... That wasn't on purpose, I was simply a drunken teenage girl. Lastly, I apologize for making fun of your work. But... if I were you, I wouldn't claim that one because it looked more like an open vagina (or even a butt hole as my 8-year-old little sister called it at the time.)"

Lovato also slammed McMullen's decision to tattoo an intoxicated teenager, writing, "I also wouldn't be admitting to the fact that you tattooed a very intoxicated 18-year-old on a tour bus without the proper judgment that most legit tattoo artists have of saying 'Hmm... This underage kid is wasted, maybe I shouldn't permanently ink a hot pink kiss mark on this girl's wrist....? Oh well... F--k it, she's famous.

"I can't blame you for getting the tattoo, I take full responsibility for that but if the issue here is you wanting credit, maybe next time you should wait for the person to get your tattoo sober so they would actually remember getting the tattoo in the first place, or perhaps you could've thought about all of this as a blessing that I forgot everything about you - that was until you outed yourself for the now internationally infamous 'vagina tattoo,'" she wrote before concluding, "But you're right, I should give credit where credit is due, and you Ashley, surely deserve credit for this one. #justputitonmytab."

Lesson learned Ms. Lovato.