I don't remember what explanation she gave--it certainly wasn't to replace a dance belt! She's my sister and I didn't get sexual arousal from this view. My interest was merely sartorial. But I do have this sister to thank for having afforded me my first leotard wear ever. I borrowed a red long-sleeved leotard from her closet (unbeknownst to her) and loved how it fit my body. That inspired me to go to a dancewear store and buy my first leotard for my very own, the raspberry one.
I guess the panties may have been intended to absorb any slight amount of vaginal leakage so as not to stain the leotard crotch. Panties being cheaper, and easier to launder or replace. I would need a woman's explanation to be able to fully understand this.
>>If you wear a pair of tight fitting laddies support knickers under your leotard and tights they do a far better job than a dance belt and they are far nicer and more comfortable and much cheaper too!>I agree, I do this all the time.[/i]