— to act snooty or snobbish, to put on airs, to pretend to be high class, exaggerating one's own importance.

e.g. Did you see how Sara acted all pinky-up on us today?

— extending the pinky finger while drinking tea. I like the following two explanations of the phenomenon:

#1 It's a throwback to medieval dining. In the days before salt shakers, you just had a bowl of salt that was sitting the middle of the table and got passed around. The pinkie finger was used to scoop up salt and then shake it off onto your food. And you largely ate with your hands. So you kept your pinkie up while eating and drinking, so that you wouldn't contaminate the communal salt bowl.

#2 Since ancient Rome, a cultured person ate with 3 fingers, a commoner with five. Thus, the birth of the raised pinkie as a sign of elitism. This 3 fingers etiquette rule is still correct when picking up food with the fingers and handling various pieces of flatware. This pinky “up” descended from a misinterpretation of the 3 fingers vs 5 fingers dining etiquette in the 11th century.

In the United Kingdom, it used to be considered a social requirement to raise one's little finger whilst drinking a beverage out of a cup or mug. However, now it is considered to be not correct.

Various Tea Times:

Cream Tea — A simple tea consisting of scones, clotted cream, marmalade or lemon curd and tea.
Low Tea/Afternoon Tea — an afternoon meal including sandwiches, scones, clotted cream, curd, 2-3 sweets and tea. Known as “low tea” because guests were seated in low armchairs with low side-tables on which to place their cups and saucers.
Elevenses — morning coffee hour in England; a snack that is similar to afternoon tea, but eaten in the morning. It is generally less savoury than brunch, and might consist of some cake or biscuits with a cup of coffee or tea.
Royale Tea — A social tea served with champagne at the beginning or sherry at the end of the tea.
High Tea — High tea co notates an idea of elegancy and regal-ness when in fact is was an evening meal most often enjoyed around 6 pm as laborers and miners returned home. High tea consists of meat and potatoes as well as other foods and tea. It was not exclusively a working class meal but was adopted by all social groups. Families with servants often took high tea on Sundays in order to allow the maids and butlers time to go to church and not worry about cooking an evening meal for the family.