What should i do????????

Im 15, and my boyfriend is 17.. he has a car but doesn't have a licence.. my mum doesn't know he dont have a license but she knows he drives.. i love him but i dont know how to tell him how i feel. and all his mates think he's cool cos he has a car.. plus his car is like broken... it runs for like 20 minutes then conks out. He knows it's illegal but all his mates keep winding him up telling him how cool he is.. and he keeps wanting to take me home and i don't want him too because where i live there are cops everywhere and i dont want to get in any trouble. my mom keeps telling me that he can take me home but she doesnt know he doesnt have a licence and i dont want to tell her incase she like tries to make me leave him or something because hes disobeying the law :/ The other day me and him went to the cinema.. and after we went for a meal. then i called my mom to come and pick me up. i told her that my bf was driving home and she was like why dont u get him to give u a lift.. and i just said cant you pick me up.. my bf is going the opposite way and he has hardly any fuel (me trying to think of something to say) so mom picks me up... and then starts questioning me about my bf.. i dont really want to talk about him to her because my moms very nosy and it is so annoying. i love my bf so much just this kinda gets me a little scared.. i dont want him to get in trouble with the police about his car.. but i dont know how to tell him how i feel without making a complete fool out of myself.. he's not the kind of person to go laughing about stuff to his mates.. hope this makes senseeee. Helppp?xxxxxx