Never go to a birthday party if you got invited

Unfortunately that has already happened to me. One of my playable sim kids got an invite to a bday from his fellow schoolmate (a townie). So he went to the party and I wasn't expecting his friend to actually age. Now his friend is a young adult, and he has no more friends his age to play with anymore. Well, I guess he could just make more friends, but I've learned my lesson. No more bday party invites! If he declines next time, the birthday person will not age, right? I hope that's right.