You aren't magic. You can't have muscle and not weigh anything. You could spend a year in the gym putting in serious work and add 20-30 lbs to your frame, you'll look and feel better, your girl will agree, and you'll have definition.

What it sounds like is you saying you want to trim your pubes to make your 3 inch pecker look bigger, instead of taking the gas station dick pills and growing a Monster can.