Was it dry before you pump or after you pump?
2 possiblities if it is due to post pump: your foremilk is basically water with slight tinge of blue else is water vapour from your body heat.
Then most likely your foremilk. Suction too strong and milk squirt out. I had the same issue but after reducing the suction for first 5-10mins and up it thereafter. The problem resolved.
Lee Suzanne