It means he wants you to contact him, usually with a phone call.
*facepalm*
so we don't hit in the face with a puck when someone says heads up.
If your name starts with a b, its just a short form, but when someone says "what is up b" The b means "bitch".
shut the hell up
To beware; be careful; be on the alert.
Well if someone says hit me up, they are trying to say i want to get to know you better, maybe you should text me, talk me, hang out with me more. They would like to start a friendship of some sort with you.
It means Hit Me Up
You will feel warmer as you make out.
You will be challenged and may or may not live up to it
it means that they have a crush on you and they want to be your girlfriend/boyfriend or wants to marry you
If someone says something is coming down the pike they mean its coming up soon
it doesn't really mean "what's up" people use it to say what are you doing or how have you been but mostly what are you doing