Junsu and Yoochun are lovers living in the same house. But Yoochun isn’t contented with Junsu so he flirts with other people and brings them home not caring about what Junsu might feel. On the other hand, Junsu loves Yoochun a lot so he just lets Yoochun do whatever he likes even if it hurts him so bad. All he wishes is to be by Yoochun’s side and for Yoochun to not leave him.
http://yoosu.paradoxica.info/chaptered/holding-back-the-tears