A weak attempt at feminism
gf: "Nah, I got my girl over. We're in a sismance, get over it"
bf: "What the hell? That isn't even a real thing, and it sounds really awful when you say sismance out loud. You just wish you had a bromance like me"
2. A form of female bonding.
3. A close relationship between two female to such a point where they start to seem like a couple.
Girl: "Nah. Are you dumb? It's a sismance. You wouldn't understand because you're a guy."
Guy: "Sismance isn't real."
Girl: "Well, neither is this relationship between you and me."