Oh, and did we mention? The naked dress was crafted from totally see-through fabric that was embellished with *very* ...

And while on stage Katy clearly got very into her performance as she lifted her tight white vest down to reveal her silver underwear. She completed her outfit ... rendition of Perry's 2011 hit ...

Rebecca, meanwhile, donned an equally short leopard print mini dress with a flared skirt. She wore black heeled knee-high ...

Just over a month after she donned a sheer corset dress that had a micro mini skirt that looked like it was made of lettuce, Katy has replicated that same outfit formula to wear another corset + ...