Coughing transmits droplets of moisture from one person's lungs/throat/mouth/nose to another's. If Science had not already taught me this, I would now know it thanks to the exhilarating mist of sputum showered upon me by your gooey baby-thing.
Now, I realize you are used to being covered in the juices of your funky little foundling--but I am not. I don't want you to think it is merely the novelty of this mucosal assault that irks me, though.
Science also teaches us that those droplets of moisture are chock-a-bock full of bacteria and viruses. Given the stream of fluid spewing from every orifice in the head of your unfortunate offspring, I suspect there were plenty of bacteria and viruses to go around.
Given that you turned your head the one time you coughed, I suspect you have already learned these valuable lessons from Science. Now, I think you should allow Science to teach you another valuable lesson in manners:
POINTING YOUR LITTLE CROTCH FRUIT AT ME WHILE HE IS COUGHING IS JUST AS FUCKING RUDE AS COUGHING ON ME YOURSELF.
For the love of crackers, man! Point it elsewhere, cover it up, leave it at home, whatever it takes! Just keep your baby slime to yourself! Science says so.