Resigning for a better job offer
Give your notice and say nothing about your next job, make a cordial exit. Or, negotiate tactfully with your boss. Don’t mention your job offer as a threat. Discuss the value you bring to the company. Express your gratitude that you can work for him, regardless if it is true. Don’t drive a hard bargain for he may start looking for your replacement immediately. Remember, employment is not all about money. Consider a different boss, the learning curve, new colleagues to size up, company culture (politics) to learn as well.