Hahaha, I have to agree with
Whirls here!!
I wear one for my job and I get enough stick about it - so unless you've got really broad shoulders (which you
will have soon from all the hovering practice and slope landings you're about to do...) - I would stick with civvy clothes!
Another thing too is that - over here anyway - it got REALLY bloody hot in that bubble after an hours' intense lesson and you hop out completely drenched - I even gave up on the limb-covering clothes and wore cotton shorts & singlet.
(As you can imagine, it looked really hot and sexy with my steel-capped boots...
)
Hope this helps!