AITA for telling my nephew that his “unpaid internship” was actually being funded by me?

My brother owns a small landscaping company. This summer, his seventeen-year-old son, Owen, worked there three mornings a week. My brother described it as an unpaid internship: Owen would learn scheduling, estimates, and customer communication instead of just mowing lawns.

I disliked the unpaid part. Owen is saving for a used car, and the company uses some of the spreadsheets and follow-up calls he completes. My brother said the experience was valuable, the business could not afford another employee, and Owen agreed.

I offered a compromise. I would give Owen $1,200 at the end of the summer if he completed the schedule and treated the placement seriously. My brother accepted on one condition: we would call it a gift from me, not wages from the company. He did not want Owen measuring every task against a paycheck.

For two months, that arrangement stayed private.

Then Owen began missing mornings. He arrived late twice and skipped one day to go to a lake with friends. My brother told him he was wasting an opportunity other teenagers would appreciate. Owen answered that it was hard to feel grateful while doing real work for free.

My brother said, “Nobody is paying you because you haven’t earned pay yet.”

I was standing in the office doorway. Before I could reconsider, I said, “That’s not true. I’m paying him twelve hundred dollars if he finishes.”

Owen stared at both of us. My brother told me to leave.

The disclosure changed everything. Owen asked why his father had hidden the money and whether the company had been taking credit for my support. He also calculated an hourly rate and complained that it was low. My brother canceled the internship that afternoon, saying the lesson had been ruined.

I still gave Owen the money, prorated for the weeks he completed. My brother says that rewarded quitting. He believes I undermined him in front of his employee and his son, violated our agreement, and turned a family favor into a wage dispute.

I think he crossed a line when he used the absence of pay to tell Owen he had not earned any. The secrecy was supposed to keep money from becoming the focus, not give my brother a dramatic speech about generosity.

Owen is now applying for paid part-time jobs. He is angry at his father and grateful to me, which is a comfortable position for me and an awful one for my brother. I cannot pretend I did not know that would happen when I spoke.

AITA for revealing the arrangement in the middle of their argument?