Perform an Angry Dragon but plug your partner's nose.
While receiving a blow job, before you ejaculate plug your partner's nose, and at the point of cumming slap down hard on the back of your partner's head. They will gag, but since the nose is plugged the semen will come out of the tear-ducts. Making your partner look like an angry dragon, with tears.
NOTE: Pull your penis out of your partner's mouth immediately after, the shock should keep him/her from biting down.
I wanted to do something really special for my girlfriend, so when she was giving me a blowjob I gave her an Angry Dragon Tear. I think I get a badge for it, because it is extremely rare.