Now the couple, who met in March at the premiere of Red Riding Hood, are engaged and looking for a home together.
"I've never met anyone like him," the Twilight actress, 23, told PEOPLE in May of the American Idol contestant, 26. "I've never met anyone who has such a good solid heart and comes from such a good solid family and is just a genuine person."
After confirming the two were "officially dating," the singer told PEOPLE that Reed was supportive of his Idol elimination in April – very supportive. "She is actually pumped," he said. "She said, 'Dude, you finally get to do your thing and be yourself and be the artist you are.' "
He continued: "She is happy about the whole situation. She has been nothing but cool to me."
A Birthday to RememberThe couple had plenty to celebrate in May: their love – and Reed's 23rd birthday.
Before cozying up on the dance floor at Gallery Nightclub in Las Vegas, Reed and McDonald enjoyed a romantic romp on Catalina Island, where they marked the milestone more privately.
"He surprised me," Reed told PEOPLE. "We rented bikes, and he had this cake made – a chocolate cake. [It was] the best cake I've ever had."
As for her gift, the actress said McDonald kept it low-key – as she requested – and bought her a "$10 necklace from a vintage store" in New York.
"We just like hanging out together," she said at the time, "and presents feel funny to me."
Home Sweet HomeThe couple already live together, but in light of their engagement, Reed told PEOPLE the couple are on the hunt for a new place to call home.
"Paul and I want a bigger place," she said. "His music is so important to him and to me, and so I want to give him a whole separate space for it."
She added: "It will be good, and it will help him be creative."
As for the skeptics who say their relationship is moving too fast, Reed isn't bothered. "I love him," she said. "And I don't care."
Reporting by MARK GRAY and JESSICA HERNDON