Last week, Sulli uploaded this picture:
Then, just today, Nam Tae Hyun posted this picture:
Fans have noted that the pictures were taken in the same setting, just uploaded at different times! You can tell from the lighting, and you can even see Sulli in the bottom left of Nam Tae Hyun's picture.
Fans were surprised, leaving comments like, "I never imagined that Nam Tae Hyun would be next to her," on her post and, "WAIT WHAT," on his post. Another reason for the surprise is Nam Tae Hyun holding a cigarette in his hand, although considering the number of people who smoke in South Korea, this probably isn't too shocking for everyone.
As for an explanation on why they're hanging out together, it appears they both were invited to a party hosted by photographer JDZ Chung last week.
Nice to see the two are getting along as friends!