To suddenly try to become closer to a member of the opposite sex before an important social event, solely for the purpose of asking them/ being asked to that social event.
Can be used in other forms, such as sharped, sharp, sharps, etc.
Dude, why are you hanging out so much with that Alison girl lately?
Oh, I'm sharping her, I want to take her to prom.
Hey, you know Shannon's only trying to sharp you, right? She wants to go to formal with you.