what exactly does "hooking up" mean...

[foonette]

So i geuss im no the most popular social type, but i used to be a fat kid and am just now getting fit.

ive really liked this girl in HS who is a senior for a while, but we stopped talking for a while...ive texted her but no replies...i will see her over summer though at a tennis camp
she is going to UCLA next year

here is the heartbreaking part- my friend told me that she is "hooking up" with this other kid...however they just met. also, the kid she is apparently hooking up with is a huge loser and everyones hates him.

could this just be the kid bragging alot? or should i just forget about her completely (i absolutely cant stand slutty girls) I know hooking up can mean anything from coffee to sex, but dont guys brag and play it up alot? she is very classy according to everyone, so i doubt shed do anything with someone she just met unless she was that shallow