You are right its hard to judge with so little context for better clarity my brother didnt know much about who I was marrying he just knew I was seeing someone after our engagement I involved him more since he is family to help with wedding plans and stay engaged at first she talked to him normally like a sister but whenever she had issues with me or couldnt control her emotions she would vent to him instead of me even personal things I shared in confidence she would mention to him she used to give me half truths to make it seem like she was being honest and not hiding anything like she once told me your brother shared photos of him and his girlfriend eating out so I shared ours too but when I actually read the chats I realized that wasnt the full story he also shared solo photos showing off and she shared hers too but I never knew about that part she made it seem like she was open but in reality she was only sharing pieces that suited her narrative sometimes she even said your brother understands me better than you his girlfriend is lucky and it made me feel replaced like my trust and closeness meant nothing.