The pair are well known to be incredibly close friends, with Changsub even agreeing to let Chorong borrow a hefty sum of money when she prank-called him on 'Yang and Nam Show'. Well, BTOB will be guests on the 2nd episode of 'New Yang and Nam Show', and he called a 'mysterious' female idol in the preview.
Even though her name wasn't specifically said, any fan would recognize Chorong's voice - not to mention that she mentioned she was in Hong Kong and A Pink was in Hong Kong recently, and that the pair often call each other when asked to call close friends. On the phone call, Changsub explained that he was going to be pranking the cast of the 'Boys Over Flowers' musical, and asked her to be his girlfriend for that day.
In response, Chorong burst out laughing and said she didn't consider him as a man at all, and then proceeded to call him an idiot.... not to mention she revealed, "You have a lot of girls!", which flustered Changsub.
Check out the preview to the episode above!