Hyoyeon is said to have broken up with her boyfriend

SM Entertainment said Hyoyeon have already broken up with writer Kim Jun Hyung.
 

 

Source: http://news.sportsseoul.com/read/entertain/1347769.htm

Accordingly, Hyoyeon and writer Kim Jun Hyung has been dating for 2 years, but now they have broke up. Source: http://news.sportsseoul.com/read/entertain/1347769.htm 

Their relationship is not publicized unlike Yoona and Sooyoung. And now, there's Tiffany.

After the incident about Hyoyeon and her so-called "friend" getting into the police station because of some alleged assault Hyoyeon caused, speculations arises that this "friend" of hers is Kim Jun Hyung. However, SM Ent already denied the rumours and took some legal actions to prevent the spread of these rumours.