My [23 M] Girlfriend's [24] dad [60is always flaunting his wealth and talking down on poor people, but I grew up poor and have been hiding it from him for years.

This has nothing to do with my girlfriend she's the best. College sweethearts through the Greek system and all that jazz. I'm getting ready to ask her to marry me in a few weeks.
Her grandpa is rich. Her dad is the head of a large hedge fund and stock market wiz. As a result my girlfriend is absurdly wealthy. Yacht and Plane wealthy. She "found out" I was poor during college but never cared or put pressure on me, but I always withheld that from her parents because I didn't want to be seen as the "poor mixed kid" that they're daughter brought home from college.
We recently moved to a big city about 20 minutes away from her parents neighborhood. Her dad also got me a job at her uncles firm in an extremely well paying position. As a result we spend a lot of time with her family.
And holy **** her dad is an *******. I've met him more than a few times but always thought he was flaunting it to show off at family functions or parents weekends. Nope. It's all he talks about. He goes out of his way to show it off.
He took us to a steak house one random night. It was stupidly expensive. $100 for most steaks. $20 for most sides
I was ordering the second or third least expensive steak and he interjects. Says "[insert my name], I don't live in the ghetto" It was joking tone, but I lived in the projects for the first 10 years of my life. he proceeded to replace my steak with the most expensive one on the menu, order all the sides for the entire table, and spend the entire night telling me how he still "balls out" and "we're not poor people, and people like us don't need to worry about money"
I kind of shrugged this off. It was supposed to be a celebratory night. He brought me an incredible dinner. Me and my girlfriend just gave each other this look and smiled through the night. Plus he doesn't know my families history.
I guess the kicker came today. We ran into my girlfriends parents in the grocery store and they proceeded to accompany us through the store. They look in our basket and start criticizing every thing that's not fresh or organic. They proceed to call soup, ground beef, and beans poor people food. "Are your cards frozen? Why are you eating poor people food?" "Are you donating this or something" then questioned why we were "only" getting chips and dip. we had to talk her dad out of catering food. It's a relaxing day. Home nachos are perfectly fine.
We're both super laid back about stuff like this. Even in college my girlfriend would eat Taco Bell and be money conscious.
I grew up being excited if I had all that stuff in my fridge. Yes, I can afford to buy ridiculous over priced groceries, but I want to live efficiently, so I can spend on things that matter like this big diamond I'm about to put on my future wife's ring finger.
This as well as him talking down on homeless people, laughing at poor people, saying all the poor Americans are lazy and he pulled himself up from his bootstraps (even though her Grandpas rich as **** too.)
Its ****ing offensive. My mom and dad weren't lazy. My dad had PTSD and a blown out knee from the military that left him 100% disabled and my mom got blackballed out her law firm right before I was born for having 3 kids in 4 years. They both hustled to give us what we needed and some of the things we wanted and when her dad ****s on poor people it enrages me because it's like he's ****ting on my parents.
I don't know what to do. My girlfriend said that if I come clean to him he might stop because he likes me, but I don't want that getting out. I'm still fairly new at my job, it's one where image matters. I've managed to avoid a lot of stereotypical assumptions because of my name, my skin tone, and because I'm from a rich county even though I'm from a poor city.
Her parents have met my parents once, but a "lawyer" and a "former military" doesn't reveal how bad we had it until I was in high school.
What do I do? I don't think I can just cut him off. Her uncle is my boss, and he's been vital to my ascension. I don't want to tell him, but hearing him **** on poor people is enraging.
Am I being over sensitive or unappreciative? I don't know. There's no one I can really talk to about this besides my girlfriend and she thinks I'm being neither.
TL;DR girlfriends dad is a rich ****** that flaunts his wealth, ****s on/makes fun of poor people. In a situation where I'm going to be near her family, and I can't stand hearing this ******* anymore because I grew up poor as **** and it feels like he's ****ting on my family. My girlfriend is not like her dad at all


Source.