He puts it to his sister while doing homework (incest)

The boy approaches from behind and begins to rub his sister's buttocks, she is lying in bed doing homework, the truth is that the girl is not immuta, her brother is rubbing her ass and she is still totally focused on his own, OMG !. So the boy puts it while doing his homework, puts it behind and the sister continues with her things as if nothing was happening, hahahaha, what a situation, I do not know who is crazier of the two, but it seems that they understand well, right? rich rich rich incest ...