The holidays have a lot of activities, family commitments, work parties and religious events. These can become "shoulds" events we must participate in either due to our own push or someone else wanting us to participate. This creates  demand-resistance. It's a deep seated, often unconscious negative reaction to the demand, even if it is reasonable or unreasonable. It brings out the rebellion in us if we had controlling, overprotective parents, or rigid school environments. The "should" makes family and couple relationships more difficult.

When you notice someone triggered by "shoulds" use words such as "prefer to go" or "it is meaningful to me". Manage your stress and decrease others trigger words.  It helps the relationship all the way around.