I feel bad for lying to my dad but I don't want to get in trouble?

A week ago I went to my older sister's apartment (she is 18) and spent the night. She had a party and I got so trashed I don't remember most of the night and I puked, I was that drunk. I am 16. I came home and accidentally let it slip to my dad that my sister wasn't at work. My dad knows that if she didn't go to work it was because she was too hungover. He told me I'm not allowed to go over there if my sister and her roommates are drinking. He didn't know it was a party with 15 people, he thought if was just her and her roommates drinking. Then he asked me if I was drinking and I said no. Then my mom was antagonizing me to say if I was drinking. They both kept asking me. They even asked my sister and she covered for me. Then I asked my dad if I could spend the night at their apartment tonight and he said no because he doesn't want me to be exposed to "bad stuff" because he think I will do it too. Let's be clear that this was the first time I ever drank and I've been to many parties before and have not drank. I am not peer pressured ever to drink. I drank this time because I wanted to. I bought the alcohol. I found my own person to pay for it. My sister had nothing to do with it. Anyway I asked him why does he always say he trusts me when he never acts like it. Like why does he think I'll be so easily influenced to drink. Then he told me very sternly "I do trust you but you better be very very very careful because if I ever ever ever find out your doing any of this stiff you claim your not your going to be in way more trouble then your sister ever was in because you're having me trust you." My sister has been drinking since she was 14. She is a huge drinker and would go to parties all the time and my parents would punish her by turning off her phone. Grounding her. Once it got really out of hand they sold her car and made her buy her own. Then they sent her to rehab. Which didn't help. So they punished her really severely and I'm really worried that he may find out. If he finds out I'll be screwed. I don't know what to do! Should I tell him or hope for the best. Help!