What significance of John's re-seasoning the soup?

John and Elizabeth's marriage is already strained by his affair with Abigail. The air in their home is cold (the relationship), and they have no zest in their marriage (seasoning). When he tastes the stew, he isn't crazy about it........ so rather than upset Elizabeth with a trivial thing...... he adds a pinch of salt himself. This is symbolic of their relationship.