Probably because Collet would see the cheer outfit, say "No" call the one holding it a "perverted pedophile with delusions of grandeur" and even if she took the outfit she'd be like "I am never wearing this - outside of curiosity..." then probably try it on, look at herself in the mirror, then take it off even quicker.
RD would have to be really freaking quick to draw her in those few moments she's wearing the outfit... and she wouldn't be holding a pom-pom aloft in a pose, she would be blushing and shaking her head like "No way!" the entire time.
*Probably because Collet would see the cheer outfit, say "No" call the one holding it a "perverted
