Why this is uncomfortable
When you eat out with the family, you are in a strange middle ground. You are not a guest — you are working. But you are also not invisible — you are sitting at the same table. The family may assume you know the arrangement. You may assume they will cover it. Neither of you wants to bring it up because it feels awkward. And so the meal arrives, the check comes, and someone feels weird.
The discomfort grows with more expensive meals. A coffee at a playground cafe is one thing. A restaurant dinner during a family vacation is another. The higher the cost, the higher the tension if expectations were never set.