Sex with a step sister/brother = incest?

Whats your thoughts on this?

I know this may seem a bit gross or whatever, but I want to know what y'all think.

In my opinion, I dont consider it incest, because youre not related by blood.

I don't consider it incest, I just consider it freakin weird.

It really depends honestly. If all you have known them as is a step sister than ya. but what if you knew them before they became your step sister and liked them? beside they still have a separate last name. if you think about it your barely even related to them by marriage.