Sometimes you screw up and cross a boundary.
Sometimes you screw up bad and really cross a boundary, or cross a boundary one too many times.
After that screw up that relationship is forever changed – or even demolished – in a way that it’s extremely difficult to come back from.
When that happens, it’s normal to get a “second opinion”. To ask your friends, family, everyone who will listen if what you did was “really so bad”.
Again, that’s normal. I know; I’ve done it. 
But the temptations of arguing with the other person(s) in that relationship, of trying to minimize what you did wrong, of offering those “second opinions” as some kind of evidence…
That’s not okay at all.
Because you don’t get to decide someone else’s boundaries.
It does not matter if you don’t understand their boundaries. It does not matter if you disagree with their boundaries.
Those are someone else’s boundaries.
You can try to work to understand them. Maybe you will – though that doesn’t mean that relationship is automatically coming back. It isn’t a quick journey. It’s taken me half a decade to really, fully, understand how I crossed those boundaries when I screwed up. I am a better person now than I was then… but people change and move on.
Or you can decide those boundaries – and therefore that relationship – isn’t for you.
But trying to pressure someone into giving up their hard-won boundaries because you broke them?
That just makes everything worse.
 It’s not really okay; it gets in the way of you learning from your mistake by trying to make the screw up into “not a screw up”. Again, I know; I’ve done it. But it is normal.