It's unhealthy to sneeze on others.
Alex has a cold, but had to work today and while on lunch break with his co-worker Mary, he feels a tickle in his nose.
Alex wants to feel relief.
Alex knows he's about to sneeze so excuses himself and does so in the bathroom with a tissue.
Alex knows he's about to sneeze but remains seated and gets mucus on Mary.
Mary is able to remain safe from getting sick.
Mary catches Alex's cold and is grossed out.