In a recent Reddit post shared by Twigs-Rain, the Redditor explained that their “husband lent all of our money to his mother” without telling them recently.

They explained that they’d recently totalled their main car, and while their family had a backup vehicle, it wasn’t big enough for their kids and was often used by their husband for work.

So, they saved up enough for a new vehicle, but their bank didn’t let them withdraw as much as they needed in one day.

To solve the problem, the poster’s husband “transferred the money to his mother’s bank so she could get the money or a cashier’s check out for us.”

Unbeknownst to the poster, though, their mother-in-law needed that £7,500-odd to pay her employees (she’s a business owner).

Without the poster’s knowledge, their husband turned what was meant to be a transfer into a loan ― and started turning down every car the poster showed her, leaving her confused and without transport.

“The fact that they made the plan together, didn’t consult me, and then hid it from me for a week really pisses me off,” the author wrote.

“It’s now been 15 days, and she still hasn’t paid us back. He says she’s waiting for a bank loan to come through. I feel like at this point she’s more of his wife than I am.”

We spoke to relationship expert Sofie Roos and Leah Levi, a psychologist and relationships expert at the safety-first dating app Flure, about what to do if your spouse lends money without your permission or even knowledge.

Just as affairs can be emotional as well as physical, Levi told HuffPost UK that your partner can “betray” you with money too.

“This kind of secrecy about money is called financial infidelity,” she explained.

“Like emotional or sexual infidelity, financial infidelity can create distance between partners and weaken their connection. It can also cause one partner to feel left out and lead to doubts about honesty in other areas of the relationship.”

Roos says that “money is one of the most sensitive topics in a relationship”, adding that a financial misalignment “can really cause relationship problems.”

Money can be tied with respect, loyalty, priority, safety, and equity in your relationship.

So, Levi says, “If your partner is lending money to friends or family without telling you, it can feel like a betrayal and damage trust in your relationship.”

Both experts agree with Levi’s advice, to “talk about your financial expectations as a couple and set clear boundaries.”

This is a clear case of the husband overstepping what should have been an obvious “boundary”, however.

If this is the case, you need to let your partner know that what they did hurt you, Roos said.

“Then ask them what their thoughts are about this, let them explain why they did what they did and how they view it now when they know how it made you feel.”

“From there, you can come up with a plan for how to deal with money overall, but also on how to deal with situations like the one you just were in, something that can re-build your thrust and minimise the risk of something like this happening again.”

As with any other boundary, if your clearly-stated financial needs are being ignored over and over again, it might be time to reconsider the relationship.