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.

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

a sexual act involving oral intercourse. When the man cums in the girls mouth he slaps her on the back so she spits it out her nose, hense looking like a dragon.

When you're receiving head and right as you climax you shove her head towards you causing a "milk shooting out of your nose" effect with your jizz

When a girl is giving you a blow job, you grab her head and make her deep throat so much the cum goes out her nose.

During sex the male cums in a female/male's mouth and punches her/him in the stomach, causing her/him to spit it out.