<human>: My girlfriend and I have been dating 3 years.  This is my only serious relationship I've ever been in.  She is pretty, sweet, nice, caring, drama free, and likable.

The problem is that I just can't imagine her being the last girl I ever date.  I feel a need to date/hook up with more women.  

There are issues, mainly I feel like I'm the center of her world.  She doesn't do much with her friends and I feel like I'm always trying to get time alone with mine.  I'm feeling pressure to get married soon and I'm absolutely not ready for that.  I also am bored with sex and want to be with others.

I just hate the idea of throwing away a sure thing.  I know I could have a story book life with her.  That just seems boring to me.

Most of all I hate the idea of hurting her.  Having wasted these years of her life.  Her family and friends will hate me.  My family will probably be upset.  I'll be alone and I'll feel like an asshole for hurting her.  I'm sure I'll regret it instantly and want her back.  I don't want her to be hurt...

I guess I'm looking for people with experiences in leaving good relationships because they just didn't feel ready or like they were missing something.

Condense the text into a few key points
<bot>: I'm not ready to settle down in a perfect relationship, but can't stand the idea of hurting her and give up on it.