I Need To Learn How To Scowl

I am standing on the platform, waiting for the metro and moving my feet in vague references to the dance steps we just worked on in class.  This guy is smiling in my direction, but I can't tell if he is smiling at me, so I just ignore him.
The train comes, I get on.
This guy stands right next to me.  And is still smiling at me.
There are only so many other places to look, especially when he then says "ça va?"
Drat.  My first and only instinct is to look at him, smile, and say "oui, ça va."
I am an idiot.

This guy ends up telling me that meeting me was fate, that he already likes me, that his heart has spoken.

I don't know how to shake such persistence without being rude, and I don't really know how to do that.  The tone of voice, the scowl, the firm shake of the head.. I just don't have those skills.
I try telling him the truth, that I don't want to give him my number, that I have had bad experiences with meeting random boys on the metro, and that I don't think this is how love is found.  I try telling him that I don't know him at all.  That he doesn't know me at all, how in the world does he think he likes me!

He is just urged on by my openness.  He follows me OUT of the train and corners me on the sidewalk. "écoute, écoute," he keeps saying, "listen, listen."  Oh, I'm listening.  He is invading my bubble (an impressive feat if any of you know how small my bubble is), and I have to shove his arm off my shoulders.  I think he just thinks it's endearing.  I need to lose the nice-American-girl smile.


And then I remember the other reason that meeting random guys on the train is a bad idea:  they very rarely (read: never) are Mormon.  And if they aren't Mormon, they probably don't keep the law of chastity.  And if they don't already keep the law of chastity, I don't want to be their first experiment with the idea!  I've done that often enough, thank you very much, and it doesn't generally work out.

Now... how to say that in French...
In the end, I said something about being really religious, gave him my number, and we are meeting up on Thursday.  I am giving him a For The Strength Of Youth pamphlet and a Book of Mormon (in French).  I will then tell him that I will be his friend, but no more than that.  We shall see who is talking about destiny THEN!

UPDATE:

I told this guy that I'm Mormon, that religion (and the law of chastity) is important for me, and that I don't love him.  He told me he believed in God, that he would marry me, and that I would come to love him with time.  He EVEN tried to tell me that he is willing to sacrifice for me so I should be willing to sacrifice for him.  THE NERVE OF THAT MAN!!!  

At a certain point I threatened to leave the cafe without him, and he followed me out (leaving his coke unfinished--oh the sacrifices!!).  He persisted until the very last second, until I grabbed his shoulder, kissed his cheeks, said good night, and walked away without looking back, hoping he would be smart enough not to follow me.  

Done.  I'm so done.  Talking to this man is like being stuck in a Escher drawing.  Though, I have to say, it took longer and was more frustrating, but I was eventually able to say no while staying myself, i.e. I didn't have to learn how to scowl in the end.  

I WANT OUT!