How do I act around him?

He is from germany and is staying with us for 6 weeks. he has spent 5 days with us. i have quite a large family. 3 older brothers and 3 younger brothers. I have been spending allot of time with him. we made a deal if I teach him to ride a horse he will teach me german. I really like him. I think that he may like me because 2 days ago he told me that he thought that i was cute then later said that he likes my accent. When I went to bed that night at about 3 am i got up to go to the bath room and i saw him sitting on the couch. i asked him what was wrong and he said nothing so i sat down and we talked for awhile then i fell asleep and woe up in my bed.today he asked me if i wanted to spend the night with him i want to get close to him. I said yes because I am guessing we will just talk again. I have never felt this way about a guy. what am i supposed to do around him? im 13 and hes 17 almost 18.