Not to rag on you, but just be careful about what your dad wants too!
Some parents want the best for their kids, and will be rather selfless when it comes to things like... well... what you're talking about.
But to be honest, if I had a Pro already... I'd probably just stick with the Pro. The Air isn't anything special unless if you travel, or if you're finding the Pro to be too heavy for your day-to-day needs. I went with the Air, though, because the Pro 13-inch didn't offer any real graphics bonuses, I didn't need the excess in processing power, the display quality of the 13-inch Pro was a bit nicer but I saw past that since the 11-inch still looks nice, and I didn't need a disc drive; I also bought the Air because it's nice and light for school, and it's rather portable. However, that said: The Pro still gets the job done, and it's still quite small relative to other laptops that are out there. Just saying.
If you get upgrade-itis over the Air like this, you'll end up switching laptops around every 6 months.