What do you think about me telling annoying customers that I'm 19 years old?
Some people think it's okay to lie to annoying people. What makes you want to lie about your age?
That's not true. Telling lies is bad.
It is good to be honest about your age, even when you are faced with annoying customers while working. You are right that telling lies is wrong and it's good that you are following your moral compass by telling the truth.
I just don't want you to force your moral compass on me.
Being honest about your age is the right thing to do. Lying to customers about your age might cause a misunderstanding between you and the customer as they will assume things about you based on your age.