Dad says that they have to buy slalom skis instead of twin-tip skis?

Oh man thats brutal! I love my twintips and would never go with anything else. With the slaloms you will get good basic ski experience down. But, if you wanna ski the mountain and spend some time in the park too..then these skis will drive you insane. Maybe try and show him some Newschool skiings vids on Youtube. Explain that you wanna do more than just ski down the hill. I know he doesnt understand, but maybe explain how it will be a waste of money getting you a type of ski that you have no interest in. It's like making you take piano lessons when you wanna play the Violin.