However, since their split, the pair have remained really close friends.
Now, Nick has some extremely kind things to say about Selena, and the recent kidney transplant she just had to have.
"I was as surprised as everyone else when I woke up and saw her Instagram," he said on SiriusXM's Hits 1. "But wow, just incredible. And the strength she's shown through all that's amazing and inspiring. And I'm pumped for her. I'm happy to see that she's doing well, it seems, and that she was able to get the surgery. And her friend helping her was a beautiful thing, so it's all amazing."
Ugh, can everyone have an ex like Nick Jonas?
He isn't the only one who has come out and supported Selena after her battle, with the likes of Lady Gaga and Kesha saying beautiful things too.