I am not sure how to put this all well but here goes.
For about maybe I would say a year and a half or so, it has been hurting when I sit for a long time like about 30 minutes or less (or more) and then get up. I dont wanna say my "butt" is the thing that hurts because it feels like what hurts is a bone located somewhere near my bottom (I really wouldnt know how else to explain this, Im not good with body parts and such). It just hurts whenever I sit for a long time and I have to get up slowly otherwise it hurts (No BIG SEVERE PAIN) but it does get iritating when Im at school and I have to get up slowly. Hope someone understood this.
I had that kind of pain decades ago, when I was in high school. Turns out, it was from slumping in the desk, sitting on my tailbone instead of the fleshy part of the rear end. If you do that, stopping it and taking ibuprofen according to directions may relieve the inflammation.
If you feel a lump on your tailbone that hurts to the touch or to put pressure on, you may have a pilonidal cyst. You should see a doctor for that.
I have been dealing with this for over 2 years and after about 5 doctors the last one finally knew what I have. If a Pilonidal cyst is what you have, it sounds like it might be at the start of it yet. When it gets infected the pain will be unbearable until it either bursts on its own or the doc lances it. I am scheduled for surgury this Tuesday. If it continues to bother I would suggest getting it looked at.
If the misery is not in the tail bone area it could be what I call the "sitting bones" over to the side from the tail bone where our weight rests while sitting. No matter how much padding a person has, the sitting bones can become very tired and miserable. Try sitting on one cheek more than the other off and on and see if that helps. Sitting a long time will cause the sitting bones to ache.
I have the same thing, thinking it was from a UTI that I had. The doc said it was just my muscles and to take Tylenol whenever it hurt. That helps alot. I find that if I sleep wrong or sit wrong it will hurt, but i've been doing fine with it ever since.