How should i treat my uncle?

i am really disgusted with my uncle. sometimes i get rides with him and have sleepovers at his house cause he has kids my age. but every time he sees me he's always making fun of my family of how poor we are. i get really pissed off cause we arent poor we're like middle class and so are they. they just overspend their money with remodeling their home for example. i mean the whole reason they r able to do it is because he takes his own mother's (my grandmother's) pension money for his own selfish needs. the other thing is that is that my grandma isnt even aware of it. so the next time he makes fun of my family for being poor what should i do or say to him?