Close contact

FIL had a meal with a friend yesterday. Today his friend got tested covid positive. FIL wants to meet baby and us for dinner tomorrow, he says he will do ART test before meeting. Will you agree? If you don't, how will you tell your FIL that you are not comfortable with meeting? I am concerned for my baby, and ourselves. His ART could be a false negative, or it could be too soon to show. My husband thinks it's okay so long as his ART is negative.