We have no idea why your husband wants to go? Maybe good reasons? If half term, parents may be very pressed. If there is no response and you suspect they are hurt, maybe there is more to this. We have to keep a sense of proportion and common sense. You don’t say whether the family are out and about and exposed, or relatively risk free, same with husband. Many families are making tough choices. I know one who from the outset have gone in and out of their daughter’s house to help with everything including childcare (has husband working from home) throughout whole pandemic. Daughter has severe life shortening and threatening underlying health conditions, had a stroke during last lockdown, both units have shielded from anyone else, but clearly against the earlier rules. But good on them - they have staved off other calamities.