@Courora it depends on the situation, only in some situations can you marry step siblings.
If your parent adopts them they can become a legal step sibling and you can't marry.
Although in the medieval times sibling marriages/inbreeding were a thing among royalty all the way until the first world war
@Master123456789 THAT'S WHAT I WAS ABOUT TO SAY!!!!! Wth author!!!!???! You just teased us for 15 (admittedly great) chapters!!!!! The most shmexy panels were in the first chapter! that's sick and wrong XD