Closest thing to a father

When Erin and Jack is getting a divorce, Nicky is caught in the crossfire and starts acting out. It falls on Frank to discipline his favourite granddaughter as now he's the closest thing that the kid has to a father. He hates every second of it but does it out of a sense of duty. But will he able to stop Nicky from spiralling? Warnings: Spanking of minor by parental figure