Lightly coat the asparagus with olive oil, salt, and pepper. Grill indirect on medium heat. Allow about 15 minutes for cooking. Grill the lemon wedge against direct heat for 5-7 minutes. Sample the asparagus as it cooks and call it done when you think it's done.
Plate the asparagus then add the lemon (acids last!). Lemon wedges on the side make a nice presentation.
You can always add more salt later!