Well my butt is in pain, i was kneed (ran up to me and hit my butt with his knee) by one kid at school in the butt and it is sore to sit on, what can ?

Injury to buttocks: You don't say how old you are, but please report this abusive behavior to an adult right away. Your pain may be a bruise or possibly even a fracture of the coccyx, which can also happen with a sit-fall. Try applying a bag of ice bits wrapped in a towel, never ice to skin. See your doctor if pain continues. ER if you have trouble using the bathroom after trauma.

Muscle injury: Your butt is in pain duo to injury caused to the part of buttock.. The skin and muscles in buttock area are sore and causing pain on pressure when you are sitting .You may apply some ice to the buttock and take some pain killer , it may give you relief. Avoid pressure on affected side .If no relief , discuss with your doctor and get examined, also investigation if needed . Hope you feel better