I (25m) am in a public WhatsApp group where people chat and go out. We're all randoms meeting each other on the internet, so the main point of the group is for people to make friends and even find that special someone.

One day, the admins programmed an outing to a restaurant, something more lighthearted than the usual pub or dance clubs. Some people started tagging me, asking if I'd be able to go. Unfortunately, I was (and still am) short on money, so I said that I wouldn't be able to attend.

One friend in specific, which I'll call him Wally, came into my DMs and offered to pay my bill if it meant me going. I told him I wasn't comfortable with the idea, because I usually spend a lot on restaurants since I eat a lot, and that I don't usually like people spending money on me for personal reasons related to my upbringing. He insisted so much though, that I ended up accepting it. That made him so happy.

Fast forward to the day of the outing, we all meet there, chat with each other and have a lot of fun. When it was time to ask for the bills, I jumped when I saw mine. It was EXPENSIVE. Not that I didn't expect it to be a lot, but I went overboard, considering someone else was paying for me.

I went to Wally and showed him my bill, saying that it's too much for him to pay it by himself and that I was paying half of it. He said that it was fine, that I needed to relax. However, when the waiter came to collect the pay, I jumped right in front of Wally and said that I was paying half of my bill. He didn't discuss it further and we paid it.

When I got home, he asked me why did I pay half if he said it was OK. I apologized for going back on my word, but I said that I couldn't afford to let him pay his bill and my mess after seeing how much I spent, that it was too much money for one person to handle and that he might've needed my share for something. He said that he understood my point, and said that it was really fun to meet me in person and that it was really fun.

Still, I feel like a jerk. He didn't say anything and talks with me just fine, but I think I should've just let it roll like we said instead of jumping the gun like that. AITA?