To be easily offended?

Six years. I supported my friend for six looong years while she bitched every single solitary day about the MIL that she insisted that they move into their home.
And then I saw a funny joke by a British woman that said something like, “My MIL looked longingly through the window while it was raining. I almost let her in.” (or something similar)
It was humorous and it was obviously a joke. But my friend decided to get offended and refused to speak to me.
It was the biggest favour she could’ve done for me.
She hasn’t spoken to me since and I’m sure she thinks she’s punishing me.
The multiple daily bitch-texts were the punishment.

It sounds like she thinks that you'll be underdressed for the occasion. Which doesn't really matter as long as the bride and groom won't interpret it as being that you couldn't be arsed to make an effort - presumably they know your style and won't be expecting the sparkles that everyone else will probably go for?

I agree with posters who say that it's a bit arrogant to say that you have "better taste" than MIL. Why not just say "different taste" instead of looking down your nose at an entire culture?

In my experience anyone who says they’re “elegant and classy” absolutely isn’t 😂

Your relationship with your MIL does not sound secure and easygoing - you shouldn't be going shopping with her, be so enmeshed: waiting for her response and then ruminating on her lack of approval. Don't do this, it doesn't seem healthy for you or the relationship.

What country are you in where “everyone wears sparkles?”

It couldn’t possibly be the US.

I think she was maybe a little too honest in her reaction but that's ok. Just adopt the same level of honesty next time she chooses something you don't like rather than politely kind as you likely would be.

You don't like her taste but you're offended that she doesn't pretend to like yours? Let it go. It's not up to her to validate your choices and you seem pretty confident in them. Enjoy your classic dress and she can enjoy her sparkles, it's not like her compliment would mean much to you if you don't think she has good taste or did you want her to see the light and ditch the sequins on the sight of your superior outfit?

Well, are you going to lie and say you like her choice of outfit ( with your taste being far superior ) or are you going to say you don’t like it?…

This sounds like a total storm in a teacup. She didn’t like your choice of dress and wasn’t that concerned to conceal it. So what, though? You know your tastes are dissimilar. Is what is actually ‘offending’ you the fact that you think she should have either lied or pretended she liked it?

She is a rude woman if she really said nothing.

Taste is subjective, yours isn't necessarily better or worse. The arrogance is in claiming it's better. Least arrogance is just a statement of fact, my MIL and I have really different taste. You sound like a little kid declaring you're best.

Ah, maybe she is worried you are going to let them down by not dressing up enough? If it is customary to wear sparkles in that country, turning up in a plain dress might be like turning up in jeans at an Indian wedding?

Yeah that does seem a bit rude as she was so keen to see it.

She didn't like it and didn't know how to say it tactfully, so she stuck firmly to the "if you don't have anything nice to say, don't say anything at all" rule.

You MiL was shocked by your choice. Given your respective styles she was probably taken aback by how plain/non weddingy/dull she thought it was and was lost for words. You'll be the same when she reveals hers and you're shocked by how flashy/garish/overdone you think it is.

You should go NC.

"Additionally, and I mean this in the least arrogant way possible, I have way better taste than my MIL, she likes ott glitter sparkles etc and I like elegant, classic styles."

Another way of looking at it could be that you like 'basic tried and tested for generations' styles that a lot of people find boring and see you as having no individuality or courage to be different.

I personally think everyone should wear what they like, but your arrogance and lack of awareness annoys me, the idea that you are superior because you prefer a different look. I personally am not into glitter and sparkles but that doesn't mean I have better taste, it's just different.

I don’t think she can win can she? You think her taste is naff, she probably feels the same. She’s taken what she feels is the least offensive route without lying.

You can’t have it both ways: if you don’t have the same taste allow her to be who she is without being either rude or inauthentic and be happy with your own choices.

Smug much OP?

I'd you don't have something nice to say don't say anything I'm guessing.

I'd put it out of my head and do a inner eye roll.

I have way better taste than my MIL, she likes ott glitter sparkles etc and I like elegant, classic styles. 😂

that's your opinion. EVERYONE has good taste and a great sense of humour.

She doesn't like the dress but didn't want to make a rude or unpleasant comment. Why do you care if she doesn't like it?

Would you ask what she would prefer and go and buy that instead? Of course not, so what's the problem?

I mean your MIl will be a bit older than you doesn't mean your "style " is better just different