She said in April: "I'm just taking things as they come.
"I'm in a magical relationship right now. And of course I want it to be ours, and low key...This is the one thing that's been mine about my personal life."
The musician, who previously dated stars including Jake Gyllenhaal, Harry Styles and Taylor Lautner, admitted the attention on her personal life put her off dating for a long time before she met Harris.
"Calvin is a really great mate and he's so fantastic, and Taylor is such a cool person who I love. I thought. 'They're both really awesome and both really tall, they'll brilliant together'."