This isn't my ouch, but it's near and dear to my heart. My oldest sister (who is blessed with the same level of grace as me... in other words, NONE!) went for a ride on our old 10-speed wearing Dr. Scholl's sandals. Remember those?!? It didn't take long for one of them to get tangled in the chain, then the spokes... OUCH!
My children are absolutely not allowed on the treadmill unless they are wearing properly tied sneakers. If it hurts someone's feelings that I judge him or her for wearing flip flops on exercise equipment, I'm good with that
Bare feet bother me because of the possibility for fungal infections that can pass from someone else's feet to my skin!