Have you thought about what you would do with it once it's time to leave the nest and you can't take your snake with you?
Have you found a good cage, good thermostat, and the other gear? You figured that cost and have it covered? You then have enough in reserve for a visit to the herp vet if ever needed?
Have you tried other snakes like a king or corn with your dad?
At the end of the day though it's his house, so it's his rules. I can see his side and I own snakes.