I can unintentionally taste my darn armpits!

Name: 
Armpit Taster
More information: 
My mouth sometimes tastes the way my armpit smells! I know the taste is coming from my armpit. Typically it happens after there has been some type of contact near my armpits while either putting on a shirt or something else. My worst fear is that someone else will taste my armpits! Why does this happen?