I'm sorry that happen, but it will happen again...and again...and again.
I think you will have flare ups from time to time. I don't know if was really about the cat or something else.
Look you know the hot points in your marriage, if not they will come up in MC. You know how to steel yourself.
My take on piecing (when I was doing it) is that there will be flare ups, but its our reaction to those flare ups that matter. My W was very good about saying during the time when we were rebuilding - "we will have R talks and we will have fights." I'm also of the opinion that a healthy marriage will have disagreements from time to time. I see a red flag when people say "we never fight," but that's just me.
Our problem last year was that the fights would spiral out of control. This year not so much.
Now it's different. I respond to my W in a different way. Last weekend she was really snippy and short with me, in between the times we had fun. I just kinda let it roll off me at the time. The only time I brought it up was on Monday after the weekend mainly because I wanted to make sure I wasn't p!ssing her off somehow.
All the same things still apply. Don't get hung up on one thing...eye on the overall picture. She apologized, accept it, move one.
There's a song I think about at times like these...
"It's not all about you You're so cynical and vain Yeah I swear you can't get out of your own way" --It's not all about you by Face to Face.
Patience is bitter, but its fruit is sweet. --Jean Jacques Rousseau.