GAG: Borrow a friend’s ChapStick® and put it on your lips. Continue to put it on your cheeks, your eyebrows, etc.
There are lots of people who carry around roll-on lip balm. ChapStick® seems to be the most popular brand. After they use the balm, some will throw it on the table. If they do that simulate what I described above. If they start to put it away simply ask “Can I borrow that for a sec?”