F.C.
M.,
When I planned and had my son's 5th birthday party, I addressed all the invitations in the kid's names. I also included a schedule: 12 noon-4 p.m. food, 1 p.m. crafts, 2 p.m. games, 3 p.m. cake and ice cream. Therefore, most people got the hint. My husband still ended up inviting about 6 adults who he thought would be insulted if they were not invited. Of those, only 2 showed up. Most of my friends with no kids heard from the way I described the party that it was just a small affair and so there was no need to hide the party from them, nor was there a need to explain why they were not invited.
Have a fun party!
Take Care,
F.