How do I get around not having my mum's side of the family in my life anymore without offending them?

My mum's side are so embarrassing and I can't stand to be around them.

They think they are so middle class and above everyone when in reality they are the most fucked up people I know.

For starters my grandma is a racist who never wanted anything to do with me growing up. All she cares about is which grandchild is earning the most and she is so rude and abusive towards my mum my mum actually doesn't notice anymore because she's had it from her, her entire life. She just expects things from her without any thanks what so ever and then tries to make her feel bad about herself too.

My aunties are both bitter as fuck because they are both on there second marriage and there kids are so fucked up they will look for anything in me and stisters to criticize to make themselves feel better about themselves being terrible mothers. They both drink and think they are so above everyone else because they work in a office and have one black friend. They think they are so woke when in reality if a homeless person asked them for money they'd think they'd been raped.

My oldest cusion is 30 and has moved in with her mum again after two failed relationships were she pretty much abused her ex's but she's the victim somehow. But besides that she's actually the least toxic.

My two youngest cusion now. Ones in poly relationship at the age of 15 been kicked out of school multiple times for smoking weed and got his own house burgled. The other is dating a man 10 years older than her (by the way her mum is with a man 30 years older than her) and did something very fraudulent to her own mum too.

All my cusions are drug addicts too

My oldest sister went to family dinner just today because my little cusion came back home even though I live far away too and barley see my family anymore but they literally don't even know exist most the time. Apparently they were all smoking weed.

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My mum's family don't even care about me. I'm the second child in the family to just buy there own house and none of them care yet when it my oldest sister who earns the most out of my family they are all down the house giving her gifts and stuff.

I'm nearly 25 and they still ask me how schools going and call me by my middle stisters name.

If I get married I don't want them there as I know they will ruin it for me and will be so embarrassing. My boyfriend is very anti drugs too
How do I get around not having my mum's side of the family in my life anymore without offending them?
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