What in the world is thinspo?

Bullshit.

That's all it is.

It's something Ты shouldn't do.

Thinspo is when Ты look at a thin person & they inspire Ты to be skinner/loose weight.
An inspiration basically(:

Basically being anorexic.... which is the worst decision to make in your life.

o_O
i don't want to look like a stick