Butterfly sleeves, do you think they are a kind of clothing? In fact, butterfly sleeves are not what everyone usually calls a clothing style, but a small defect that seriously affects a woman’s figure. So, what exactly are butterfly sleeves? What kind of small defect is called a butterfly sleeve? Plastic surgery experts from Beijing Lidu Hospital will answer your question. How effective is arm liposuction? 》》》Click to consult an expert... Located on the inner side of the arm, under the armpit, there are often two pieces of fat, which we vividly call "butterfly sleeves". The "butterfly sleeves" are located on the triceps brachii (the back edge of the upper arm). Since this muscle is rarely used, even very thin girls often have these two pieces of soft fat. , butterfly sleeves make the whole figure look bloated.