The Latte is Mine: Brandy and Monica appear in ad promoting Dunkin's new Cereal ‘N Milk Latte

Brandy and Monica nearly argue over Dunkin's Cereal 'N Milk Latte in a new ad promoting the brand's latest drink. The two are spotted in a dressing room as they attempt to figure out the owner of the one drink on the table.

"This is mine, right?" Brandy asks, to which Monica responds, "I gotta be honest, I thought it was mine." "Not yours," Brandy claps back. "But mine," Monica says, grabbing the drink from Brandy.

Brandy puts an end to the back-and-forth, deciding not to go down the same path they did years ago on their 1998 song "The Boy is Mine."

“We are not doing this again – can someone get us a Cereal ‘N Milk Latte please?” asks the "Full Moon" singer, who is immediately given another latte from someone off camera.

"When two great things come together, it's harmony," Monica says.

The new Cereal ‘N Milk Latte, which blends espresso with cereal milk and a marshmallow flavor, is now available nationwide.

It arrives ahead of Brandy and Monica's co-headlining The Boy Is Mine tour, which is set to kick off in October.

"The song was such a monumental song and so many people loved it, but it just never just seemed like it was the right time. But now coming together all of these years later, it just seems like this is the perfect time," Brandy tells People of their upcoming outing.

Monica teases the trek will be filled with surprises, as they "aren't sharing any details about it."

“One of the things that is so sorely missed ... you don't get the chance to just be genuinely surprised like you used to back in the '90s," she said. "That was something that was always a plus because you didn't know what to expect, so you were so happy as you were experiencing it.”