Why should I give your mom a discount?

Ever since I started this job I've been plagued by a rampant hatred for our friends and family discount policy. If you work at the cafe, you get 40% off all your purchases. Well, that makes sense. I, for one, work hard for every dollar I earn at that joint, so hell yeah I deserve a discount on my day-off cheese cake and latte indulgences. Not that I hang out where I work on my days off...
The immediate family and closest friends of an employee also receive a 40% discount on everything. It's not uncommon for a business to be generous with its discounts in this way, and I actually think it quite nice and quite fair. After all, shouldn't the woman whose womb I infested for nine months be honored with slightly cheaper espresso? And my boyfriend, who I live with and who keeps me sane and satisfied; he obviously deserves the discount. So my issue is not with who the discount applies to, it's with the outrageous sense of entitlement some friends and family of my co-workers possess.
I shudder when a customer loudly asserts that she is the mother of whoever after she places her order. No matter that her son or daughter isn't even working at the moment to confirm or deny this woman's claim. She speaks it, therefore it is the truth. I think it's entirely unclassy to proclaim your familial status in order to knock a dollar off the cost of your soy cap. It's rude and inappropriate.
My stance is that it's only okay to ask for the discount if the employee you're related to or screwing is present. Otherwise, keep your mouth shut.
If your friend or family member isn't behind the counter, do not assume a "don't you know who I am?" attitude. Just pay full price, and appreciate this peaceful moment of anonymity.
Where I work, there are some parents of employees who come in every day and order really extravagant beverages simply because of the discount they expect. Considering that some of their sons or daughters only work part-time, and don't really work that hard, I feel taken advantage of.
My mother, bless her little heart, always finds out when I'm working and only comes in to the cafe on my shifts. The rare occasions where she comes in and I'm not there, she keeps her identity quiet, though most of my co-workers know who she is and automatically discount her purchases. She realizes that the family discount is a special privilege, not to be abused at the expense of cafe profits.
The bottom line is this- employees work for their discount. Family members and friends don't. Family and friends don't deserve a discount. It is a bonus, a gift of thanks for bestowing their son, boyfriend or cousin upon our cafe and helping make it a better place. That's all.