Search Results: still not over my ex

Imagine a situation where:
-Older Brother (30): In a committed relationship for 3-4 years, living with his girlfriend.
-Younger Brother (27): Had a tumultuous, on-again/off-again relationship with a woman (25) over the past year.
-The Ex-Girlfriend (25): Struggled with the relationship due to repeated cheating, emotional conflicts, and mistreatment by the younger brother

When the Ex-Girlfriend First Reached Out to the Older Brother, He Was Supportive and Neutral → Initially, he listened, gave neutral advice, and didn’t seem to have a strong opinion about her or the relationship.

-However, After That, the Older Brother Became Harsh & Judgmental → Over text, he started expressing strong dislike toward the ex-girlfriend, saying she was manipulative and toxic.
-The Older Brother Has Reached Out Multiple Times to Confront the Ex-Girlfriend → Instead of ignoring the situation, he actively engaged with her in texts, being dismissive and harshly critical of her role in the relationship.
-The Ex-Girlfriend Tried to Explain Her Side → She reached out to the older brother to show him the full picture, explaining that she had been hurt, cheated on, and mistreated. However, the older brother ignored this perspective and continued blaming her entirely for the toxic cycle.
-Even After the Breakup, the Older Brother Still Feels Strongly About the Situation → Despite the fact that the younger brother and the ex-girlfriend have broken up, the older brother continues to speak negatively about her and express strong feelings of resentment toward her.

What do you believe are the primary reasons for the older brother’s intense and harsh behavior toward his younger brother’s ex-girlfriend?

My friend called me this week saying that I say unnecessary things & those things take jabs at her. She's a "girl's girl" & some things sound like I'm competing
She gave me 2 examples out of many
1. She said someone was talking to us about shoes & I said I got them 1st (i specifically dont remember that moment, but I'll give it to her because people don't remember things unless it's attached to a filtering emotion)
2. She mentioned how her ex talked & hugged her & I said he does that with everybody
(That I explained as protection cuz they broken up twice & I've had my own breakup in which my ex liked me physically but didn't want to be with me
I know her ex is not extreme like that but I didn't want her to get her hopes up on something he does to everybody
She should look for other signs.) She still said I shouldn't say it like that
I could understand what she means however while we're in conversation I thought that phrase was precise & got my point across quickly & she never brought it up to me until now
How was I suppose to know she didn't like it & how am I suppose to hold a conversation & know which comments are unnecessary
In general conversations are unnecessary unless you need something from the other person (health/businesswise) Then she said she's upset that she keeps having to find out information from my ex in terms of my dad being sick or me being sick (my ex only knows because we still work together & when he ask wya, i tell him) but her schedule is random I don't know when she's sleep, on the road, etc so it's up to her. When I did reach out, it was at the wrong time, so I got tired of doing it. Also when I told her I was sick, specifically what I was going through, it felt like she forgot or didn't look up what's happening to me for herself. And when we went on outings/convos when my sickness played a role in our interaction, empathy wasn't present, so why tell her? Should I let her know or let it fade?