lit. cut sleeve (idiom); fig. euphemism for homosexuality, originating from History of Western Han 汉书:emperor Han Aidi (real name Liu Xin) was in bed with his lover Dong Xian, and had to attend a court audience that morning. Not wishing to awaken Dong Xian, who was sleeping with his head resting on the emperor's long robe sleeve, Aidi used a knife to cut off the lower half of his sleeve.
断袖之癖，汉语成语，拼音是duàn xiù zhī pǐ，指男子的同性恋行为。
原指男子的同性恋行为，现男女不限。
《汉书·董贤传》：“常与上卧起。尝昼寝，偏藉上袖，上欲起，贤未觉，不欲动贤，乃断袖而起。”