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