I can`t be sure if this is down to cycling : but as i`ve been doing a fair bit lately it seems a logical explanation.
My human anatomy knowledge is a bit poor so excuse my terminology here.
i`m getting pain, inside of thighs at top near joints. I guess this is where the femur goes into the pelvis.
what could cause this ? is my saddle too high ? or is it the pedals ? or the saddle ?
i`m going out at the weekend on a ride and want to get this sorted. It doesn`t hurt so much when i`m riding .. more when i get back and sit down. Walking is fine.
I would look at your pedals first and increase the float if possible. Saddle and saddle height problems almost always show up while you are riding and would be more likely causes of butt pain or knee problems.
Your problem seems unusual in my experience and may be worth consulting a doctor. It could be problem unrelated to but exaggerated by cycling.
Note: I am not a doctor, I just play one on the internet.