"Usually I don't care, but this one is so ridiculous I had to say something," the "Baby" singer wrote after reading an article about the two dating.
Selena Gomez is rumored to want to launch a new reality television show in order to rebrand herself after her breakups with Justin Bieber and Zedd.
"Selena is tired of being seen as Justin Bieber's lovesick ex, so she's hatched a plan to do her own reality show," a source told OK! magazine.
"Selena thinks a reality show could boost her career."
The "Heart Wants What It Wants" singer was previously reported to be upset at Justin Bieber because he was sending her mixed signals.
"Justin basically acted all into her the night of the ball [Met Gala 2015] and the following next two days, and then just disappeared," a source told Hollywood Life.
"Yes, she's angry, but more so fed up and disappointed with his inconsistencies. She says she should have known better."
Selena Gomez is also rumored to be upset at rumors suggesting her ex-boyfriend Zedd is dating her friend Nina Dobrev. The music producer is said to be attracted to the "Vampire Diaries" star physically and wants to start a relationship with her.
"A few things are holding stuff back. He is scared to be in the tabloids again and she doesn't want to upset Selena," another source also revealed to the site.