Read Aporia Manga:
The safe word is "cafe latte". After meeting at a VVIP club lounge, Gyum and Ja-wook agree to enter a Dom/sub relationship. What Ja-wook fails to mention, however, is that he's not actually a masochist, and that he's just doing this because he fell for Gyum at first sight. Unfortunately for Ja-wook, Gyum is a known sadist among the club circles with a smile that's hazardous to the heart - and now, the clueless first- more.. timer finds himself coming up with safe signals and waking up with bruises after intoxicating nights with his dom.