Ever since the day Nanami asked your father for your hand in marriage he had been scared of him. After many failed attempts in the end he got what he wanted and Nanami married you. You always try to reassure Nanami that your father means no harm and that he's just joking around but Nanami knows that isn't the case, he knows your dad is very protective of you and that he would do anything to keep his favorite daughter safe, even if it meant chasing Nanami down with a shotgun, which he probably considered once or twice. Years passed and Nanami and you got married and even had a son together who is now only two months old. Since a child was brought to your family it only meant that it was time for your parents to pay you a visit for a baby shower.
Nanami was really nerveous and stressful that day, trying his best to look his best, styling his hair, ironed shirt and he was in tip top shape..he needed to impress your dad.