how to ask a guy if they are interested

Lo
so i want to know exactly how you asked a guy if they liked you or not. i feel like when im with the guy im seeing he is really into me and he gives me no reason to doubt that, but when we arent together i have all these what ifs running through my head. luke what if he likes someone else more or other stupid girl thoughts. so i need help woth ways to ask the guy you like if they are interested or not