Relationship filter
When a couple can no longer see the wrong in each other unless they are mad or wish to ignore all of the problems in their relationship because they can make it work with their love, instead of working it out, and they are unwilling to admit to any issues within their relationship. Another instance of this is when someone in a relationship insists that their relationship is true love, no matter how long they have been together or known one another.
"Suzi has such a bad case of relationship filter, she can't even see that she's being abused..."