You should definitely ask. Thats what I did. Well, before I even started though:-)
The worst you'll get, is a no. That just shows you are willing to try out new positions! BUT STRETCH!! :D
definitely ask! your coach will admire you for wanting to try something new, and if youve got the flexibility and the balance i say go for it! you never know, you could be a natural and become center flyer, good luck! (: