lit. the broken sleeve / euphemism for gay (men)
上嘗與晝寢。嘗晝寢，偏藉上袖，上欲起，賢未覺，不欲動賢，乃斷袖而起。其恩愛至此." -- 出自《漢書·佞幸傳》
Dong, Xian and Emperor Ai of Han often shared the same bed. One day, the pair were taking a nap together as usual. When Emperor Ai tried to get up, he realized Xian’s body was resting on the loose sleeve of his hanfu robe. To prevent awakening Xian, Emperor Ai cut off his sleeve. Such shows how intense their love is.