What does it mean when you have a friends with benefits with somebody?
It is a sick thing - it means that you have a sex buddy. No strings attached. Someone who uses you until they find someone that they really like. Or they already have someone and they want someone else too for their extracurricular activities.
You have sex without being in a relationship...
Friends with benefits mean that you are friends but you do stuff like kiss and hold hands like boyfriend or girlfriend would do and that you don't actually go out.
Your not going out but you make put or have sex