How to tell my parents i have a boyfriend?

im 15 years old nd a guy i realli lik, likes me too. He has asked me out n i said tht i need tym to decide. I dont want to lie to my parents who i luv so i want to tell them bfr i say yes. My parents r kinda strict so im very nervous about telling them. Plus they dont reali approve of him, bt i kno tht he has changed. Pls hlp me think of wat to say