someone who makes you fall so hard for them then let you go because they like hurting people. or they just love the feeling of you being hurt. or they want to see you upset. this can be an ex boyfriend, a friend, a sibling, a relative, or a teacher
The kind of guy most girls ACTUALLY want when they say they want a Nice Guy.
Jerks are selfish, manipulative bastards who see women as little more then sexual conquests to brag about to their buddies or mere objects that are there for their personal pleasure. As to ensure the post-sex breakup will be in their favor, Jerks often play the "sensative guy" early on so the girl will make most of the moves on HIM, and after he's done with her and dumps her for some other girl just like her, he can make it look like she's at fault for coming on too strong, and consequently she'll take him back if he chooses to return for seconds.
Typically are/were Frat Boys, Jocks, and Preps in school.
"Yeah, Billy's a real Jerk the way he used Tricia like that. Can't believe she bought his crap though."