Is it permissible to attend a family gathering on the occasion of Mother's Day—despite the impermissibility of celebrating it—to prevent greater harm, or is it permissible to feign illness to avoid going?

Celebrating what is called "Mother's Day" is disliked due to its imitation of non-Muslims, and because Muslims are not in need of such customs. However, if the husband's mother is accustomed to gathering the family on this occasion, and the husband becomes angry if they do not go, then there is no harm in going to avoid the harms that would result from not going, especially since some contemporary scholars deem it permissible if it is free from sharia (definition) violations. If these harms can be avoided by making valid excuses to the husband without lying, while using allusions and dissimulation, then we hope there will be no harm.