Comedian Shin Dong Yup revealed Brian's past secret relationship.

On March 28th, Brian was a guest on KBS Joy's blockbuster quiz show, 'The Chair Korea Season 2' and honestly answered questions thrown his way.  During the questioning, MC Shin Dong Yup attacked him with a certain story that left the singer unable to hide his embarrassment.

During the OX talk time, MC Shin Dong Yup revealed a time that he caught Brian in the midst of "skinship" with a woman.  It turns out, Brian was getting physical with a female celebrity he had been dating at the time, and Shin Dong Yup happened to witness the whole thing by chance.

Shocked by Shin Dong Yup's account of the situation, Brian froze and could not say anything for a while. He eventually asked Shin Dong Yup not to reveal the name of the female celebrity causing a commotion on the set.

During the episode, Brian also revealed that he, "has not had a girlfriend in the past five years."  He also claimed, "I forgot how to talk to women," surprising the audience.

Source: OSEN via Nate