After a similar experience, like others have noted, we invite one or two friends to a birthday event. We have done things like go to a movie or bowling and keep it pretty low key. We typically have a separate party with family. Our son’s school is horribly cliquey so our attempts at trying to create relationships with parents have been unsuccessful, particularly as he has got older (he is in 4th grade now) and his behaviors have become more distinct to the kids.