People.com said the couple posed for photos together at Sunday's MTV Movie Awards.
Reed was wearing a bauble on her left ring finger as she told E! about McDonald. "He's the one," she said.
DISCUSS AND COMMENT ON THIS STORY Reality TV World now offers Facebook Comments on our stories. To post a comment, log into Facebook and then 'Add' your comment. To report spam or abuse, click the 'X' in the upper right corner of the comment box.