Sibling Birthday Invitation Wording I Need Help Wording Birthday Invitations?

I need help wording birthday invitations? - sibling birthday invitation wording

OK, so my son and his 6 years in school. I'll have a glow in the dark golf. $ 8 per child, and I am willing to pay for child guests. The difficulty lies in 7 of 8 of them are brothers and sisters. Although I can not say xxxx only permitted to say as the word of the invitation that the child is asked to pay, but the brothers do not? I have never done before. Most of the time was in our house, where he was "free" so to speak. Nor goodies bags, including golf, instead of shining in the dark matter.