Have pimple in my inner thigh that hurts were my underwear line is doesn't have a head to pop it and it just hurts when i try to pop it?

Boil: A boil is a localized infection in the skin that begins as a reddened, tender area. Over time, the area becomes firm, hard, and more tender. Eventually, the center of the boil softens and becomes filled with infection-fighting white blood cells from the bloodstream to eradicate the infection. This collection of white blood cells, bacteria, and proteins is known as pus. You need antibiotics.