Incest Pictures Exchange Is It Incest If Its Conjoined Twins ?

Is it incest if its conjoined twins ? - incest pictures exchange

My friend showed me pictures of a child sixteen years old or something (s) with two heads, and he asked me, well, if they, kissing or masturbation, incest is?
Because they are virtually the same, but do not believe that the same brain?
What do you think?
This is a rather chaotic, I know, but I want opinions