Last christmas eve i had sex with my 25 year old sister. After the christmas party we were pretty drunk and decided to go home. I joined my oldest sister because she was super drunk and might pass out before she gets home. So when we reached the door she said she might need help up the stairs, so i helped her. When we got upstairs she fell on me and we both fell on the bed. Then we both laughed and she stopped and looked dead serious in my eyes for about 20 seconds. She suddenly started to kiss me on the lips and i was in shock. She climbed on me and pushed me against her. My body just took over and i just joined. We massaged each other for over 30 minutes and then got to the sex. We had sex for about an hour before i came inside her twice. She wanted anal as well so we could continue having sex. The next morning i snuck out when she was still asleep and i don't know if she remembers. She's pregnant and thinks it's her boyfriends' when i know it's ours.
What should i do??