Friend once coughed some up on my pants . Gave me a bit of a shock ).

And I had a perfect circular blister on my hand because I put one out with my hand. Unfortunately I had been the first one to light my glass out of five or so people, of which a few of the more squeamish ones had trouble getting theirs started.
So anyway the glass just sucked itself onto my skin and when I finally got it off it hurt like... well... something that hurts a lot
Lovely stuff, just wish it wasn't so sticky.