A phrase used to express glee when an fortunate event occurs that allows the individual to get something or "come up" on something for nothing. In lamest terms, getting something for nothing.
I saw that basketball player leave his locker open. I'm gonna get some new shoes on the come up.
We're gonna see Batman cheap during the matinee and watch three other movies that day on the come up.
To work yourself into the proximity of your desired subject with the sole purpose of shamelessly hitting on them. Said subject is usually aware of your stalking and may be seen rolling her eyes and muttering, Lord, he is creeping up on the come up AGAIN!'
Ok, ladies, stick together. Keep an eye out for nerdlingers trying to creep up on the come up!
When they first met, he thought she was just creeping up on the come up but as it turned out she wasn't skeevy like that at all.
when you're holding up your phone and making faces at it, as though you are taking a selfie, but you're really taking a picture of the person across from you or the wall or anything else that seems interesting but you don't want to be caught dead taking a picture of.
This action is often made more convincing by wiggling the eyebrows or opening the mouth, to pretend you're trying to get a Snapchat filter to work.