The drama started when Justin took exception to what fans were saying about his new ladyfriend, Sofia Richie.
Then Selena stepped in: "If you can't handle the hate then stop posting pictures of your girlfriend lol - it should be special between you two only," she wrote on his now-shuttered page. "Don't be mad at your fans.. They love you."
Justin responded: "It's funny to see people that used me for attention and still try to point the finger this way. Sad. All love."
Then he huffed off.
He's not on Snapchat but is still on Facebook, where he posted a photo of his new dog:
And he's still on Twitter, where his Instagram ordeal has spurred a trending hashtag: