I don't think its dumb at all, what I do think is it is bad timing. Let your son have his day. Let it be about him. That is 1 reason I did not go to cousins wedding, it was there day.
After its all over email, call or get together with those u trust & tell them, it may just go better than you think But I would put money down if you did it on your son's day YOU would a total flop.
Good luck & congrates to your son.
Hugs...................................Janelle