how do I make it obvious to someone I like them

I like this boy. I'm pretty sure he likes me as well. how does I make it obvious to him that I like him without my friends realizing. i am secretly hoping he will ask me out. my friends would probably tease me for liking him cos he can be a bit imature but I think he's cute. And we're from a country school and when we go to high school next year i will go to a flash place in the city and he goes to another country bumpkin school. is it worth it even though we will both part ways in 6 months. We are both 13 btw