Post coitus, a man ejaculates into their partner's mouth and then proceeds to tickle their partner to cause them to laugh forcing the ejaculate through their nasal cavities and shoot out of their nose, thus creating white whiskers resembling that of a dragon's.
"I gave my girlfriend a White Dragon and she said it burned her nostrils for a week..."
When a woman is going down on a man, right before he ejaculates he pushes down on the back of her head (or punches her in the back of the head) causing he to choke and cough thus shooting the semen out her nose. Like a dragon shooting flames or ice of it's nose.
See, sticky dragon or Ice dragon
"ohh, ohhh! almost . . . " Shove squirt Gag "BooYa! White Dragon!"
When you're giving head and a man is so far to the back of your throat that, when you swallow, some goes up your nose like milk and out your nostrils. Could look like a chinese dragon's white mustache, or breathing ice, fire, steam from out of your nose, like a dragon.