MY cousin proposed me!!!I'm sooo shocked!!!!!!What to do???????plzzzzzz help me?

My cousin has proposed me,he called me but then he said he hasn't the guts to tell me so he would send an sms and he proposed me in the sms,but it's not possible,in our religion cousins r like brothers and sisters and doing such thing is a sin.He says he always admired and loved me,since childhood as we r grown up together except whn i came to live in a foreign country where he has also come now.what to do?I?m so shocked.