Same thing as a normal treesh, except instead of having intercourse with a lot of people, you have no intercourse whatsoever with anyone.
Can also be used as "Reverse man treesh" which means the same thing except for a man.
Person 1: "I have so much sex"
Person 2: "No, you're just a reverse treesh"
Person A: "You're an idiot!"
Person B: "Me? You're the one getting pressed about a 16 year old trolling you over Twitter you reverse man treesh"