It is when you shove your dick deep up someone's nose and cum. Since your dick is in so deep, when you cum, it comes out her eyes in the form of tears. It's called the Dirty Lil Wanye because it will look like Little Wanye's tear drop tatoo around his eye.
Guy- Can I Dirty Lil Wanye you?
Chick- Hell no!
Guy- Come on, you will look just like Lil Wanye.
Chick- Damn, really? Ok.