I accidentally lit my ex girlfriends lawn on fire
Was the fire really an accident?
Yes, I didn't mean to do it.
If it was an accident, then you shouldn't be too ashamed of things. You need to learn that fire is really dangerous and can cause harm to a lot of things and you're only making your ex hate you more.
If I feel wrong, it's wrong.
Yes, it's often true that if you feel bad about something, you probably should never have done it. It's best to stay away from your ex and her house.