Ahh... don't let it bother you. I have a confession to make. Before I had Yorkies I would have laughed at a doggie party too. Clothes for dogs -- not me! Hundreds of dollars for carriers, toys, beds, etc. -- not me! LOL! Then along came the sweetest dogs in all the world who live to be loved and all that changed. Both my husband and I spoil them to extremes but I won't expect everyone to understand. If they haven't had a Yorkie yet, they just don't know the secret. But don't get peeved at them. Just smile and be content that you do know!
As far as the party -- have it if you want. But if everyone does not celebrate it with the same devotion as you, don't worry -- Benji will not care as long as he gets some attention and treats!