Strange question - twitching butt?

So I have a weird question, does anyone's butt twitch rapidly after walking/exercising?  

Everyday I go for a half hour walk, and after each walk my butt twitches like crazy. None of my family or friends experience this. Granted I definitely have more junk in than trunk than them :P 

Am I alone in this? 

I know my legs will do that after I worked out. It is just your muscles. Try drinking more water as well. It should stop the more you work out.

Nope, not alone! It happens to me, too. It does get better with time, though! I still get itchy sometimes doing cardio, my butt especially lol! Unfortunately I can't scratch my behind in the gym!