Why am I embarrased to poop in front of people?

Im being serious. I was at a birthday party of my close friend. She brought over people. And we played spin the bottle. And it pointed to me. But i didn't think anyone saw. So i spun it again an it landed on me again. And i had to poop in front of like... 12 ppl including some guys. And everyone pooped so i wouldn't feel bad. But i was the onlyone who didn't. ( in a toilet. ) but is this an awkward phobia?