Siouster Share definition Flag means either your father had a female child with your mother's sister or your mother had a female child with your father's brother. Stranger: How are you guys related to each other. You: She is my Siouster. Siouster by Sakurakage February 28, 2022 0 0 Get merch Get the Siouster mug. Buy Now — $32.95 See more merch
