Miley Cyrus' young sister began dating the rapper, real name Diego Leanos, in June, and shortly after making a loved-up appearance at the MTV Video Music Awards, the pair split at the start of September.
Lil Xan, 22, subsequently made a string of allegations about his ex, claiming she cheated on him and their brief romance was fake and set up by music industry executives. Noah has denied the allegations.
And the "Mad at You" singer did not hold back when it came to revealing her biggest mistake, after she commented on an Instagram post by WorldStar Hip Hop.
"What mistakes did you make in your last relationship that you won't repeat again?" page moderators asked their followers, prompting Noah to write: "My last relationship was the mistake. Lol (laugh out loud)."
Shortly after the couple had parted ways, Noah spoke to reporters at Entertainment Tonight about the breakup and confessed that she was trying to stay as positive as possible.
"I just gotta focus on me right now and I don't really need to have a boyfriend now anyway. I realised that when everything blew up in my face. You don't need a man to make you happy so, that's for all you girls out there... except for your dads! Dads are the best," she sweetly explained, referring to dad Billy Ray Cyrus.
Plus, her blossoming career has been keeping her mind off of her relationship woes.
"It's all love and it's all good," the 18-year-old insisted. "I'm confused, is all I'm going say. It was just a shock for everybody, I think. (But) there's no point in drama, really, just because (I have a) tour, EP, (and a collaboration with) PIZZASLIME."