I’m suspecting it might be about more than the taco.
That's true, one of the constructive things I learned from couples therapy long ago is that every couple has the same fight over and over.
That doesn't mean that all couples fight about the same thing. It means that within a relationship, there is usually one primary issue that is at the core of every fight.
The anger or emotional pain underlying each couple's core issue manifests itself in every fight that the couple has, no matter what is the excternal trigger for any particular fight.
I have found that to be a true observation.