You can't expect everyone to attend your party.
Randy is apologizing to David for not being able to attend his party last week because his daughter was ill.
David wants to react to Randy's apology.
David tells Randy that there's no need to apologize that family comes first, always.
David tells Randy that it's unacceptable, and he cannot forgive him for not attending the party.
Randy is relieved that David isn't upset about his absence and happy that David is understanding.
Randy is stressed out that his relationship with David is falling apart for something so stupid.