I can tell you exactly how to fix the problem and what mindset you're not in just by your examples you gave: You describe the story perfectly... you show the rising action (the fight), the climax (meeting the old flame), and the conclusion (reconciliation with her spouse). You got a good "Who" "What" and "Why" succinctly described... you forgot your setting questions: "Where are we in these three scenes?" "When do they happen in relationship to each other?" "How did they happen?"
For your first example, a fight between a couple can happen anywhere: Was it at home? Was it in public? What room? Where in public? Were other people able to hear it? Was it at lunch time? Bed Time? Wee hours in the Morning?
If it was at the house, clearly Old Flame didn't burst into their home on coincidence (or maybe he did... his radically different path in life is that he's a proffessional criminal and just happened to pick that moment to rob the house... but hey, I'm assuming that's not the case). Where did she meet Old Flame? Why did she think to go there? Why did he go there? Does she frequent this place or does he? How can both frequent it if she hasn't seen him in ages? Are they at a cofee place? What does he order? What does she? Is it unusual for them? Is it the same thing they've always got when they were dating? What's different about him now? What's the same? Is she happy for him in his new path? Is she disappointed with him?
When she makse up with spouse, how does she return? Where do they meet? What's he doing when she meets him?
Dialog does not take place in a vacume. It's okay to lean on the dialog for the scene, but keep in mind there is a whole world going on around them. Pay attention to the details... how do the characters move through the scene. Understand that in real life, people don't just communicate with words, but with tone and inflection on the words and with how their body moves when speaking.
"Yeah, Sure," She said tells me she's agreeing, but I can't read tone? Is she agreeing to an offer to do something wacky and unusual for her to help lift her spirits? Or is she conceeding to her dialog partner's painful truth that she knows is right, even though she doesn't like that it's right? Or is she sarcastically responding to the dialog.
To help, you might want to go to places that inspire your story settings and play the dialog in your head... don't read it from the paper, but get into your characters heads... then move through the scene as if your actually engaging with someone in this dialog. In theater, the term for this is called "blocking" and actually has to be considered in the set space because not all stages are built equal. Actors and directors will work through where the characters have to move as the give their lines and set up for future actions. While story writers can just picture it in their mind, some will often block out the scene so they can describe the flow of people through the room.
Another way to practice is to pay attention to people beyond their words when you talk to them.