So gross.
No one wants your sweaty armpit on their shoulder. It is so offensive. All slimy and stinky and gross. Yuck.
I am 6’0″, so the number of people who can do this to me are less. The shorter someone is, the worse the problem tends to get. Still, it happens. I have even done it, before I realized how offensive it is.
I had a friend do it the other day. He was just in the middle of being “wasted I love you guy”, and planted his stinky armpit on my bare shoulder like a suction cup. He just wanted to show affection. I ended up getting as far away from him as possible.
The way it happens; Someone hugs you and accidentally rubs their sweaty armpit on your shoulder. Then the huggee spends the rest of the day smelling the hugger on their shoulder. So rude. So nasty. So unacceptable.
How to stop it; When hugging someone, keep your armpit off their shoulder. End of problem.