nipple bite

I was in a lake and doing a handstand in water about five feet deep. I was trying to hold the pose and my breath as long as I could. Suddenly my concentration was pierced when I felt a sharp pain in my right nipple. It felt like someone had thrown a sharp rock at me, but since I was under water that didn't really make sense. I realized something must've bitten my nipple and bit it pretty hard. I felt violated, absurdly, and was a little skittish to get in the water for the rest of the day. I had to laugh at myself.