HOW are you a jerk?? ... The girl obviously wanted to sleep with you on the 'first date' too .. otherwise it wouldn't have happened. She's developing feelings for you are you aren't for her ... too bad for her! ... i mean come on, its not your FAULT that you haven't developed feelings, it just didn't happen. Just be honest with her -- "hey, i'm not really looking to get into a very serious relationship with you at this point in time" -- chances are she'll take it just fine and you might still be able to have some fun too
AND TAKE THE "I'm a jerk" OUT OF YOUR TITLE ... ITS NOT LIKE YOU INTENTIONALLY SCREWED SOMEONE
AND TAKE THE "I'm a jerk" OUT OF YOUR TITLE ... ITS NOT LIKE YOU INTENTIONALLY SCREWED SOMEONE