“She’s a trash-talker,” says Matt Taitelman of teammate Nancy Landy. “That’s how this all started.”

By “this” he means the bet. But let’s start at the beginning.

Matt and Nancy signed up for the Office Challenge in August, eager to shed a few pounds that have crept up over the years. They’re coworkers at the Center City law firm Zarwin Baum; Matt is an attorney, who’s been with the firm for just over a year, and Nancy, a legal assistant of 17 years.

“I was in good shape when I started working here,” says Matt. He was fresh out of law school, where a freer schedule had afforded more time to go to the gym. He estimates that he’s put on 25 to 30 pounds in the 14 months he’s been with Zarwin Baum.

Nancy’s busy, too, at work and at home, where she says her responsibilities as wife and mother often supersede any “me” time she hopes to work in to her schedule. Her husband set up a makeshift gym in the garage—a treadmill, free weights—but before the contest, Nancy had hardly found time to use it.

“When we were chosen for this contest, I said to my kids, ‘Look, from September to November, you’re not going see me,” she says. “That was that.”

Fast forward to October, as the contest was reaching its halfway mark. Matt says Nancy, trash talking as always, was really laying it on thick one day. So he blurted out: “I bet I lost more weight than you.”

She told him to put his money where his mouth is. And so they did: They bet that whoever lost fewer pounds at the midway weigh-in would have to pay for the other person’s ingredients for the weekly recipe for the rest of the contest. It was on.

The week of the weigh-ins, I got an email from Zarwin Baum team captain Patricia Holden, asking me what Nancy and Matt’s numbers had been. When I asked why and she explained about the bet, I chuckled and sent along the numbers. Matt was down six pounds; Nancy had lost nine.

“I screamed when Patty told me,” says Nancy. “Matt just heard it and knew he’d lost.”

Matt’s been paying the piper ever since. And Nancy says because Matt’s footing the bill, she doesn’t scrimp on ingredients. Like for this week’s recipe, which calls for nutmeg, Nancy said she was running low on her stash at home, so she added a jar—the largest she could find in the spice section, of course—to her shopping cart.

Matt reimbursed her yesterday—every single penny.