Your son-in-law's grilling steak for the family because we're celebrating the birth of our daughter's second child this past weekend. He looks for the missing steak knives in your cupboard because he knows there should be more. You quietly tell him those knives are impounded at the police station.
Even though the moment passes and he graciously nods his head, the reminder that this is one more celebration your son cannot join in kind of puts that familiar weight on the joy. Sorrow and joy are constant company.