So I (26F) have my late grandma's ring. Nothing fancy - thin gold band, tiny diamond. She gave it to me when I turned 18 and said "for your future." I wear it on my right middle finger since she gave it to me and it's literally the only thing I have from her. My brother Jake (28M) got engaged to "Maya" (27F) last weekend. Around 3 weeks back he asked if he could use grandma's ring for the proposal. I told him no. It was given to me specifically, and I want to keep it for my own engagement whenever that happens. At their engagement dinner - this Italian place mom picked - I was wearing the ring like always. Mom asked to see it & at that point I didn't think much of it. I showed my hand and everyone did that "aww" thing. Then mom goes, "Let's see how it looks on Maya," and reaches for my hand. My stomach just dropped. I said "No, I'm not giving it to her." Jake laughed like I was joking. "Come on sis, just let her try it on. We can get it resized later." Maya actually held out her hand toward me. I pulled my hand back and said, "It's mine. Grandma gave it to me." The whole place seemed to go quiet. Mom called me selfish. Jake said I was ruining their night. Maya looked embarrassed and pulled her hand back. Dad tried to calm everyone down but Jake stood up and left with Maya. Mom followed. Next day I woke up to like 15 texts. Jake said I humiliated Maya over "a piece of metal" and that keeping it "in the family" means giving it to his fiancée. Mom said grandma would want it worn as an engagement ring, not on my "random finger," and that I was being dramatic. Look, I get why they wanted it. Sentimental value, maybe money's tight, they're excited. But it was a gift to ME. I'm not trying to be difficult - I just want to keep the one thing she chose for me. The whole "let her try it on" thing felt like pressure in front of everyone. I probably could've handled it better, maybe talked privately instead of refusing at the table. But they already knew my answer from weeks ago. AITA? Part of me wonders if I should've just let her try it on, but once it was on her finger at their engagement dinner, getting it back would've been way harder.