It's "panties are". Some clothing-related nouns, like panties, are always used in a plural form and take a plural form of a verb.
It's "panties are". Some clothing-related nouns, like panties, are always used in the plural and take a plural form of a verb.
My panties are wet.
My panties is wet.
The phrase "a pair of panties", however, denotes a single entity and requires a singular form.
There is a pair of panties in your drawer. (not "there are...")
When using other verbs (fit, look, have, lay, etc.), follow the same rule.
These panties lay smoothly against my skin. (not "lays smoothly...")
Note that we always use a plural determiner or pronoun (these, those, them, etc.) with plural nouns (like "panties").
Those panties are cute! Do you like them?
A partial list of clothing-related nouns that only have a plural form, and therefore take "are":
