what is a neg??

uhm...try the search function
But a neg is a backhanded compliment...like you are essentially insulting her but its not an insult if that makes any sense. For example...
"Is that your real hair? oh..well it looks nice anyways"
"Where is the off button on this girl?"
"Is she always so needy?"
"I love your shirt! I saw a girl wearing the same one earlier tonite!"
You are sort of insulting her and at the same time not insulting her. We use negs as a means of tearing down bitch shields and also lowering her value. Take her out of the mindset that she is the shit and establishing yourself as not like the rest of the AFC's in the room who walk up to her and say "hey baby im glad i got my library card cause im checking you out!" (actually if i saw that in real life id probably piss my pants) It shows her that you are not phased by her beauty. It also is used to keep her attention focused on you.