Coffee

See, I envision this as something that a semi-normal someone might think of as a slightly unusual yet perfectly fine way to make coffee, but that would baffle a coffee snob.

Boil plain tap water in a pot, or maybe a plain beaten up old kettle, if you never one. Bring it to a full boil.

While that's going on, pull out your nicest coffee cups - like if you have the ones with the little saucers, that's great. Put them on a tray with a doily if you have one. Put cream and sugar in formal containers, with a special small sugar spoon (or tongs if you're going with sugar cubes). Have some small pretty napkins to go with, maybe a bud vase with a rose and some baby's breath.

Get some ground (or maybe instant?) coffee and put it in a couple of those single-serving tea infusers. Put them on the tray as well.

Let them see you in the kitchen, pouring the water from your manky beat up pot/kettle into the fancy cups. Put everything on the tray and bring it out. Then blithely put the tea infuser into the cup and let the coffee steep at the table-side, like if you were having tea.

It's fancy enough to have them questioning whether this is some special way of preparing coffee that they're just not aware of (or maybe a new TikTok trend), but it's really just you messing with them.