I have never had pimples or acne except on my butt. what could be causing this? how can i make it go away? please help it makes me very insecure.

Often this is due: to sitting on your bum either at work or exercise. Try treating your bum like a baby's bum - destin and corn starch. If not better you may need to see doctor for prescription. It is treatable so don't worry

Pimples.: you must be sweating when you sit ,that causes acne. Use more porous (cotton) clothing and change position frequently and keep yourself dry. Use antiperspirants if you can.