It's not okay to make a joke at a funeral
Frank is attending the funeral of his father in law.
Frank wants to support his family through their grief.
Frank offers his condolences to those mourning.
Frank makes a joke about the body at the funeral to try and liven the mood.
Frank's family feels that he cares for them and feels closer to him.
Frank's in-laws are not amused by his joke and ask for him to leave.