According to the fine folks at CouponBirds, $13,510 is the “financial fidelity” threshold for how much one partner can secretly spend before the other half squawks.

I chewed on that information while swallowing the receipt for a large chocolate milkshake. I’d be in a heap of trouble if my wife found I out I’d lavishly bought a $3.59 milkshake.

I can’t imagine slipping a $13,510 purchase under her nose — not to mention, actually having $13,510 in my possession. I had to dig under five cushions and poke through dozens of dust bunnies beneath beds and dressers just to scrounge the $3.59.

I once caught Terry with an empty Burger King cup. She blushed and mumbled, “I needed a coffee. I’m sorry that I didn’t ask first.”

“Sweetheart, you don’t need permission for a cup of coffee. Our budget can handle a cup of coffee. I’m not upset that you didn’t ask. I’m upset that you thought you needed to.”

“Thank you for understanding,” she said. Then her eyes narrowed. I knew that look. I’d walked right into her trap — again.

“Coffee is cheaper and healthier than a milkshake. I would advise you against such surreptitious spending again.”

That’s the day I began swallowing receipts rather than tossing them our trash.

According to the CouponBirds survey, sometimes both parties in a couple are frugal and sometimes both splurge. (Where I live — Cheapskate City — $13,510 isn’t a splurge, it’s a plunge into insanity.)

In its survey, CouponBirds asked how much the party of the first part would allow the party of the second part to part with without consulting the party of the first part before the party of both parts falls apart.

In Massachusetts, it’s a staggering $23,416. The low (?) end of the scale is Rhode Island at $2,389. Here in Ohio, the financial fidelity threshold stands at $12,480.

I’m not sure what the threshold is in stately Cole Manor, but apparently, it’s less than $3.59. I did get away with spending 50 cents on a can of stress-relieving Play-Doh. But the brow furrowed when she found out I actually bought three — red, blue and yellow — when one can would do.

If I ever made a clandestine purchase of $13,510 — or a Massachusetts power move of $23,416 — I’d better come home with a new car to replace her clunker. Or a dozen eggs. Something that expensive needs to be useful. A truckload of Pop-Tarts purchased of my own free will not only means I crossed the fidelity threshold, but also that it won’t be safe to cross the threshold of home anytime soon.

How does one go about trying to siphon such a huge chunk of change and expect to get away with it? She’s bound to notice if a wall-sized TV replaces the rinky-dink one in the living room.

Maybe it happens in the same world where those crazy car commercials are made, the ones in which you go out and buy her a brand new sedan or pickup, complete with big red bow, and instead of blistering your hide because the electric bill is due, she giggles, “I love it!”

Perhaps the best threshold is to just give her the cash, shut up and drink your milkshake. Who knows, maybe a hot new set of wheels will show up — made by Mattel.

Send donations to Cole at burtseyeview@tribtoday.com, the Burton W. Cole page on Facebook or at www.burtonwcole.com. He promises it won’t cross our special fidelity threshold.