How to tell your parents you are dating?

one day after school when my mom was picking me up she seen me and a boy kiss n hug bye. She ask me who he was but at the time he was just my friend. She got a little upset. I am 16, He is 17, my birthday is December 3 and his is June 25. That Sunday we started (finally) saying and telling people we went together. Everyone (even teacher) were like awww its about time. Anyway how am i gonna tell my mom i go with him he told his people, and also my father he is more layed bak so it will be easier to tell him. How will I tell them?