I’ve fucked up big time

My friend Courtney's staying at mine for 2 weeks to do work experience at my work with me cause she lives too far away. She's been here a week already and I haven't seen Tom in ages so Tom came round yesterday for a few hours and we went to maccies and whatever. Then he wanted to get back for a car meet but obviously he didn't wanna leave so he wanted me to come with him and I did. Courtney stayed at mine and she didn't mind. I didn't get home till 12 and Tom stayed the night. Courtney was fast asleep when we got in and you can guess what me and Tom did.. we got carried away and yeah things happened in the heat of the moment and I know it's really fucking awful regardless whether she was asleep or not but I know she woke up and she knows. She's been moody with me all morning and nothing's really been said. It's all a mess I'm a horrible person