Most Helpful Girl
You are Obviously an honest girl so why stop now? He's Not your type, you're looking for much more, and the chemistry is Not the kind of sparks and fourth of July you are Into with him.
Although in 'Four days' it's Michael's Big day, and you're in a party pooper problem here, I believe, so as to Not to top his cake with any Bad icing, perhaps it would be Better to Wait until after the fact. Buy him a special gift, not too mushy, for even friends do this for one another, but when it comes to locking lips, just explain to him you are not feeling well.
Let things go for a few days, and when you are able to see him face to face Again, sit him down and Then explain to him how you feel. Of course he will be distraught and heart broken, but it's best to end it now, then a few Months from now, when he is really Hooked on More than your lips... And I don't mean This in a sexual way. I am talking about just You he would be attached to.
If he has a hard time in you both being friends, then tell him you are sorry, but that's the way the party ends... Tell him you are Not ready for a Real Relationship at this time, you're still too young, and you're Only looking for friends right now.
Good luck. xx