McDonald and the 23-year-old Twilight saga star got engaged in June just seven weeks after the 27-year-old singer confirmed they were dating to Reality TV World, People reported.
"I love him and I don't care," Reed toldthe magazine in May, referencing how the couple had been together for only a short time.
Speculation that the couple had gotten engaged surfaced shortly prior to the People report when the Twilight, New Moon and Eclipse star flashed a diamond on her left hand's ring finger while walking the red carpet with McDonald at the MTV Movie Awards this summer.
"He's the one. He's the one," Reed told E! News at the awards ceremony when asked if she and McDonald were ready to tie the knot.
McDonald -- who made it to American Idol's Top 8 but then became the first male finalist eliminated from the show's tenth season -- met Reed when American Idol's finalists attended the premiere of Reed's The Little Red Riding Hood movie in March. An American Idol broadcast showed Reed approaching McDonald and gushing that she felt he was "amazing" and "was blushing."
McDonald subsequently told Reality TV World in April that he was in a relationship with the actress, who will co-star in Breaking Dawn, the Twilight saga's fourth installment that will hit theaters next month.
"Yes. Me and Nikki Reed are dating. It's officially true," McDonald said, putting the rumors to rest.
"She's super cool. She's super smart and a really cool girl. I'm happy with it. We've been hanging out here and there and we're both pretty busy. But it's been fun so far."
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