Instead of express negative emotions verbally they project those feelings in their behaviors toward a spouse.
They can be self-sacrificing, up to a certain point.
They can make an emotional investment, up to a certain point.
As a result, conflicts don't get resolved, you are left reeling in negative emotions and they are left feeling relieved they've escaped engaging. The more detached the passive aggressive appears to be during conflict the more anxiety you begin to feel over the realization that this person is not emotionally invested.
This is the most important person in your life, refusing to do what other couples are able to navigate…marital conflict and connect emotionally.
For a marriage to succeed it requires intimacy, self-sacrifice and emotional investment on the part of both spouses.