Seeshay is another was of saying "Cishet" to avoid certain algorithms. Using Seeshay gives you +2 defense against getting Zucked.
It's derived from imagining how one pronounce the spelling of "Cishet" in another language, then converted into it's simplest phonetic spelling.
"I don't date Sheesays"
"Why does it feel like every Seeshay with a kink think they are LGBTQ+?"
"What Sheesay?"