Caught and Dead

This is the story of what happened today and how my life ended in 2 sec. I've been dating my boyfriend for a year now & his family invited me to a trip in another city with just them and him. Everything is going fine. We are all sleeping in the same room. i have my separate bed and my bf and his little brother has another bed. My dumbass and my boyfriend decide we are horny and want to test the limits. i'm 18 and he's 20 so we are of age. We are about to have sex and then his mom wakes up and goes to the restroom. (we were on the floor between beds) She saw us. I got so scared that i peed myself. yes, you read right. i fucking peed myself. and he was under me for a sec before moving away. so i peed on him a little too. but mostly on the floor. i still have a full day with them. and it's 4 am and i can't sleep and my boyfriend is scared for tmr bc he's 100% postitive she's going to make us break up and everything is just so fucked. I'm upset about the breaking upset about the breaking up but i'm more upset about if we don't how they will look at me and treat me. Nothing will ever be the same. I just don't know what to do or how to get over this. I'm just glad i don't live with his family. I'm like a golden child so when i hear that people are disappointed in me, i get upset. and his dad expressed his disappointment and i love this boy so much. and i love his family but thats all gone and out the window now. I'm fucked. Sorry i just needed to rant somewhere about how my night/early morning went. 
Update : his brother is 16. which still isn't right but he knows what sex is.