The Breaking Dawn star and her American Idol alum beau are engaged, a source confirms to PEOPLE.
Posing together at Sunday's MTV Movie Awards, the couple showed off a sparkler on Reed's left ring finger as she told E!, "He's the one."
And to those who are concerned that the pair may be moving too fast, the actress – who is reportedly house hunting with McDonald – has an answer.
"I love him and I don't care," Reed told PEOPLE in May.
"I've never met anyone like him. 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. We have the exact same sense of humor. I've never laughed so much with anyone as I do with him."
News of the engagement was first broken by E!'s Marc Malkin on the red carpet at the MTV Movie Awards.