How do you get your parents who hate guns to get you an airsoft gun?

Join a SERIOUS airsoft team(You must be skilled to do this), most will let you borrow a gun, and make sure they know that they are holding you back from getting into a sport.

Make sure they know the difference. I know gun control Obama worshipers are completely ignorant on the subject (see Washington DC gun ban), but make sure they know that no one can be badly hurt by an airsoft gun (unless you are being equally ignornat and not wearing eye protection).