Why do i keep getting pimples on my penis after masturbation? the pimple is usually on a hair and has a thick white almost solid pus followed by some clear liquid. they don't itch or hurt and aren't tender. can this be herpes?

Acne: This is actually an uncommon variant of acne. Wash yourself often, and use some good quality lube. It's no danger to yourself and not catching to anybody else.

Poor hygiene: Sounds like you have a mild case of folliculitis (similar to acne) caused by poor hand hygiene, or poor hygiene in general, in your groin. Use soap and water to cleanse your groin area. Wash thoroughly before and after masterbation. See a doctor if the problem persists, you may need additional treatment.