Tea Party Beneath the Waves
The prospect of liquids kept underwater is tricky, but a combination of variances in density and simple magic allow soups, potions, and teas in the deep sea.
Over the last several centuries, underwater tea parties have become all the rage. While deep sea farmers cultivate kelps and sea slimes, the most popular flavors come from The Above.
The acquisition of said teas comes from a variety of sources, some legitimate (gifts and trade with travelers) to the illicit (piracy).
Please do not take away that tea is some mystical, unknowable or rare commodity. And for the love of the moon, DO NOT offer it with the airs of gifting an unknown delicacy. The ocean floor is littered with the bones of travelers and adventurers who foolishly treated mermaids as ignorant savages. Tea is a luxury because of the pleasure in enjoying it with friends, new and old.
If you are invited to an underwater tea party, dress in accordance to your comfort.
If you are a formal person, feel free to style your hair and makeup dramatically. Flowing gowns, scarves, and jewelry are very popular as the currents will whisk them this-way-and-that. Perfumes will mix with your surroundings, so choose them carefully.
Modest outfits are certainly acceptable but you may be a bit overshadowed. For folk who do not wish large amounts of attention, this may be ideal.
Should you find yourself feeling a bit like a sandbar, every good underwater tea party host keeps a spare armoire or chest of jewelry and outfits. Simply take your host aside and ask if they have anything to help you spruce up. It will not be any trouble, I can promise, as shipwrecks are common, gatherings are meant to be enjoyed, and human treasure is not aquatic currency. If anything, you are helping your host clear out old junk that has no doubt been piling up (possibly for centuries).