Gen Z friendships have entered their nickel-and-diming era

Getty Images; BI Some Gen Zers will Venmo-request you for half an avocado.

Venmo and Zelle may have made bill-splitting math easier, but they haven't made etiquette clearer.

An etiquette expert shared the best way to approach bill-splitting and handle friends who don't pay back.

When Joanne Wang went out for dinner to celebrate her 24th birthday, she expected to split the meal evenly.

She was spending the evening with a new friend, so she figured they would each pay for their own order.

When her friend decided to bring her boyfriend along at the last minute, Joanne didn't think it would complicate the economics of the dinner.

Instead, Joanne said, the new friend and the boyfriend ordered oysters and calamari — appetizers Joanne couldn't share because of her shellfish allergy.

They also had two more drinks than she had each.

At the end of the night, Joanne's new friend put down her card.

Imagine Joanne's shock when she received a Venmo request for an even, three-way split.

Happy birthday! Joanne, now 26 and an MBA candidate at the Wharton School of the University of Pennsylvania, texted her to explain why she believed it was unfair to split the bill evenly.

She said the friend made an excuse about being bad with math and sent her an itemized receipt, leaving Joanne to puzzle out how much to repay her.

Bill-splitting has always been awkward.

But for Gen Z, which came of age with Zelle, Venmo, and other money transfer apps, it has taken on new dimensions.