How should i ask this guy out?

so one of my friends (bob)(guy) has this cuzin. i like bob toward the end of the school year. but we are just friends, and staying that way, which is cool. he knows i like him. well this summer (beginnin) his cuzin started texting me... got my number from his cuzin... well lately we have been talking alot more. we have text and talked on the phone. his voice is stuck in my head. and he says the same thing about me. we havent ever hung out together yet. but i kinda already like him.. is that ok? and how do ask him to hang out what should we do.. he likes bball and football.???