Brown hamburger with green pepper and onion, drain.
Add to crockpot, or return to stove top.
Stir in ketchup, water, Worcestershire sauce, chili powder, mustard, red pepper flakes, paprika, black pepper, and sugar.
If in crockpot, cook on low setting for 1-2 hours or until heated through. If using stovetop, heat over medium-high heat until bubbly, then reduce heat to low and let simmer for 20 minutes.
Enjoy!