Definitions by Top10Slang.com

Nah Ins

This phrase is basically when you see a hot relative and you don't wanna make it weird and sexual.

My aunt is sexy, nah ins.
Nah Ins, my cousin has a fat ass.

When your relative is hot but you don't wanna make it feel weird. The word "Cest" Originates from the word "Incest".

"No Cest My Aunt Is Hot."