I sometimes don't pick up my dog's poop.
That's very inconsiderate. Why would you leave your dog's poop for someone else to pick up?
I don't want to see the other neighbor. He's so stupid and I hate him so much.
So your dog is pooping in your neighbor's yard? That's very rude to let that happen and not pick it up. You should keep your dog confined to your own yard or walk him on a leash and always pick up his poop.
Well then I guess I'll just stop walking my dog. There. Solved that.
You need to take your dogs on walks. Dogs need exercise in order to stay healthy. Don't you want your dog to live a long time by giving it plenty of exercise?