Although there are plenty of images of the pair smooching and walking hand-in-hand from 2009-2010, the first public acknowledgement of their relationship came in October 2011 when Kristen called Rob her boyfriend in an interview with GQ magazine.
The next time the pair mentioned their relationship publicly was under adverse circumstances in July 2012.
The two broke up a few years ago, but Greene said that she and the other cast members knew there was something happening between them before it became public news.
Life imitated art when Pattinson started dating his Twilight sweetheart at some point in 2009.
She was asked a number of questions on being part of the Cullen gang, including if she had a crush on any of her co-stars.