These days, we all know that Mike Berk and Ximena Cuellar are over.

We don't yet know exactly what broke them up this time ... or all of their ups and downs over the past year. Not yet, anyway.

In this sneak peek for Sunday's 90 Day Fiance: Before The 90 Days, Ximena is wedding dress shopping.

She gives Mike an ultimatum: he pays for her breast augmentation, then they go through with the wedding.

In this sneak peek clip of Season 5, Episode 10, Ximena and Mike are shopping together.

Well, "together" is a strong word.

Ximena is trying on wedding dresses. Per tradition, Mike cannot even gaze upon her during the process.

Ximena loves it -- the dress, the veil, all of it.

She repeats multiple times that she feels like a "princess."

Though we know that these two do not get their happily ever after, it's a sweet moment.

But Ximena cannot help but note to the cameras that she can't fully enjoy this yet.

The truth is that she is not entirely happy with Mike at the moment.

To her credit, she does sit down to speak with him about that instead of simply letting it fester in silence.

Mike asks her how she is feeling.

Ximena starts with the positive, honestly expressing how she felt wearing the wedding dress.

Again, she says that she felt like a princess, adding that she felt divine. It's very sweet.

But ... why is Mike willing to pay for her to get a dress if he hasn't coughed up the dough for something else that she wants?

Ximena wants a breast augmentation.

She had already tried to line one up (with funds from a loan shark) before Mike's arrival in Colombia caused her to cancel.

In part due to the language barrier (honestly ... any couple can have communication issues, but they both need to work on this), Mike is confused.

The automated translator does a decent job ... sort of ... of conveying what she said.

Even once Mike understands what she is saying, he doesn't quite get the why.

Why, he wonders, does Ximena want larger breasts?

She tells him that she might be able to find work as a model.

(Real talk, a lot of 90 Day Fiance alums do modeling work, and some can be very successful)

Mike doesn't seem to grasp her exact motives ... or is perhaps uneasy discussing this on camera.

He offers her what he hopes are reassurances that she, and her breasts, are perfect as is.

If Ximena is doing this to make him happy, she doesn't need to. (Oh, Mike)

There is something of a generational divide, even though they are only ten years apart. They have different beauty standards.

Mike is 34, and grew up in the '90s and early aughts, when small breasts were part of the mainstream beauty standard.

Ximena was born in the late '90s and grew up in the '00s and twenty-teens, an era of ever-growing butts and busts.

Plus, taste is always a factor. People in any era of fashion can simply have their own preferences, through nature or nurture.

Ximena explains that she's not doing this for Mike.

She is doing this for herself.

Ximena even has a specific timeline in mind.

She would like to go in for surgery to get breast implants the day after Mike returns to New York.

Some want to be around loved ones while they recover, but presumably Ximena will be looked after by family.

Ximena has been relying largely upon Mike for financial support.

This is not speculation -- her own family said as much when they noted that, if she and Mike split, she'll have to get a job.

She noted to the camera that perhaps a breast augmentation could help her to land a career modeling and bring in money.

After laying out her argument, Ximena hopes for a positive response.

We are reminded of a teenager who has come up with a compelling argument for why their parent should let them do something.

That's a fine dynamic for a sugar baby and a client, but a little odd to see between partners who are planning to marry.

Ximena asks bluntly if Mike will "pay for my boobies" now that she has listed the reasons for which she wants it.

The best that Mike can offer is a "maybe."

Honestly? It feels like code for can we please discuss this off camera.

This is when Ximena proposes her ultimatum -- at least, that's what it sounds like.

First, Mike can pay for her breast augmentation.

Then, and only then, can he buy her the dress.

The implication is clear, because they're not going to have a wedding without a wedding dress.

Ximena wants to get married with a fresh set of honkers, so to speak.

And if she doesn't have them, then well, she's in no rush to get married.

Mike is not thrilled to hear that, and who could blame him?

It is perfectly healthy and normal to set boundaries in a relationship, including explaining what is and is not a dealbreaker.

But demanding that someone pay for cosmetic surgery before you'll marry them? That doesn't sound like a romantic partnership.

In this moment, we are reminded of 90 Day Fiance legend Larissa Lima, who once asked on-again, off-again boyfriend Eric Nichols to pay for her breast augmentation.

However, this was fakery concocted by producers to give her and Eric a conversation and to prompt a (negative) reaction from viewers.

But ... unlike Larissa, who is one of the richest 90 Day Fiance stars of all time, Ximena's question seems much more authentic.