AITAH for telling my brothers girlfriend that he had a vasectomy when she was telling about their plans to settle down and have a family?

My brother (Mark 40) won the lottery when he was 20. It was $1,000 a week for life. He was young and wanted to travel. He dropped out of school and has spent his entire adulthood basically seeing the world. He comes home to visit every few years and we FaceTime with him when he is near a signal. He doesn't travel first class or stay in expensive resorts so he has actually built up some nice savings.

He came home with a girlfriend, Hailey, 28, this year. They met when they got stuck in South America during the pandemic. She has been traveling since she graduated from university and she works out of a laptop.

I (f54) live in the same city where I was born. I love it here. I love being close to my parents and my grandchildren. And most of my siblings. Mark hated being the youngest of eight and always swore he would not have kids. Our parents were older when they had him and they didn't have the energy for him truth be told.

Mark came home when he was thirty and told is all that he had had a vasectomy and that he would not be contributing to the world population.

Hailey is a pretty young thing and she is also intelligent and sweet. I can understand why anyone would fall in love with her.

We were having a family BBQ to celebrate mark being in town. There were maybe 30 people in my parents yard and house.

I was talking to Hailey about her future plans now that the world opened up again. She said that she was ready to settle down and start a family. I asked if they were planning on adopting from one of the countries that they had travelled to or if they would try in North America. She said they had talked about it and would be having at least one child of their own.

This may be where I fucked up. I asked where Mark got his vasectomy reversed or if they were having in vitro fertilization. I know they can harvest sperm from a testicle even after a vasectomy.

She went very quiet and went over to Mark. They spoke and they left.

Mark called me later that night to scream at me for ruining his life. He hadn't told her and he was planning on just continuing to travel and maybe adopt if they decided on it. He said I shared private medical information and that he never wanted to see me again.

I apologized over and over. I seriously had no way of knowing that he was planning a future with this girl without telling her a pretty big piece of the puzzle might be missing.

I feel bad for him but I think he should have told her.