:( my parents walked in on me and my bf?

im very embarrassed right now , i know im gonna get criticism from all of you but i need help im very scared , okay yesterday night my parents went out together , and and my bf were lef to ourselves , so about an hour after there gone me and him were laying down on the bed playing the playstation and we kinda got intimate and that led to us doing it ,(it was my first time :3 ) now me and him were still going when my mom walked in asking us did we want anything to eat and then she went quiet and backed out of the room , i sneaked out of my house to his house and havnt gone back yet cause im to scared , i mean she must of told my dad , i dont want to go back , they will kill me , and it was just in the moment ya know , we didnt expect them back early . and now i dont know what to do . were both 15 almost 16