Though the public has only just found out, Us Weekly reports that Watson and Knight actually broke up closer to the beginning of this year, after dating for two years.
Of course, the lack of information about the couple - no one even knows how they first met - is no surprise. 27-year-old Watson is notoriously private, refusing to answer questions about her love life in interviews.
"I want to be consistent: I can’t talk about my boyfriend in an interview and then expect people not to take paparazzi pictures of me walking around outside my home. You can’t have it both ways," she explained to Vanity Fair back in February.
"I’ve noticed, in Hollywood, who you’re dating gets tied up into your film promotion and becomes part of the performance and the circus. I would hate anyone that I were with to feel like they were in any way part of a show or an act," she continued.
Watson also noted that she's stopped taking selfies with most fans so as to avoid giving any "tracking data" about her whereabouts.