You can have a tea party for both boys and girls without loosing the interest of the y chromesome.
The key is finding a theme that is diverse enough to entertain both. Try a mad hatter tea party, that way your young gentlemen can find a crazy hat and enjoy the day’s festivities. OR divide your paty into 2 parts of one theme… like a Farytale party that can entertain both young knights and princesses or maybe pirates and princesses (You never know- They may even try a scone!)