I don't Know what to do !

There's a guy I see and is really cool, and I like to chill with him (and kiss him), but every time I talk to him on the phone there's always a moment when he talk about sex (just to know I'm virgin). Plus, he says to me that he want to have sex with me, but I promise to my mom that I'll never have sex before marriage, but this guy make me... Wow... and he invited me in is house "just to chill he says". If I go and I have sex with him, I feel like I do something wrong. But he tell me that sex is not a crime. I just... I really don't know what to do ! 
(Just to know again, I'm not really good in English because it's not my first language, it's French, so sorry if you don't really understand ?)