"It's a recent engagement," a source told People.
"They're just two people who found love quickly and make each other happy all the time. They both started talking about it this past weekend. It's nothing they've been hiding."
Ariana confirmed the news on Twitter by responding to the well wishes of fans.
There is a lot of speculation she already debuted the engagement ring, after she rocked a giant diamond sparkler while performing at Wango Tango on June 2.
Davidson had already shocked the Internet when he debuted two new tattoos dedicated to his eternal love of a few weeks.
So you can imagine how Twitter is taking the engagement news. Here, the most hilarious stunned responses.