On March 14, 2019, Choi retired from the entertainment industry, amidst allegations of being involved in bribery and sharing of illicit sex videos and pictures, a part of the Jung Joon-young KakaoTalk chatrooms, first revealed in the Burning Sun scandal.

Choi attended University of Suwon, majoring in digital music alongside former band member Oh Won Bin.

This group was formed to help take up some singing time during their concerts, so that lead singer, Lee Hong-gi, would not overstrain his voice.

He made his acting debut as a supporting character in the film You're My Pet (2011) starring actors Jang Keun-suk and Kim Ha-neul.

[19][20][21] With fellow band member Song Seung-hyun, Choi modeled at the 2009 Autumn Seoul Fashion Week on October 17, 2009 for Lee Ju Young, the designer of the "Resurrection" collection.

[22] On June 29, 2009, he was featured with Core Contents Media's soloist Hong Jin Young as one of the main characters in her music video "Love Battery".

[23] In March 2019, Choi was revealed to be a member of an online group chat that shared sexually explicit videos of women filmed without their knowledge or consent, together with celebrities Lee Jong-hyun and Jung Joon-young.

[12] In April 2019, police booked Choi for illegally filming women without their consent, distributing a total of six videos, and bribery to cover up his drunk-driving incident.

[26] On April 19, 2019, a woman came forward to SBS funE, claiming that five men including Choi, had raped her after she was intoxicated in March 2016, and then shared the footage in a group chat.