No, the person in front of you has not split her pants, but what she's wearing might have infringed this patent (had it not expired). Granted today back in 2002, the patent is titled, "GARMENT HAVING A BUTTOCKS CLEAVAGE REVEALING FEATURE." The patented trousers include various see-through cutouts, labeled as 12 in the drawings below, that reveal the top portion of a wearer's backside. Thankfully, this wannabe fashion trend failed to catch on, and the patent was allowed to expire in 2006 due to non-payment of maintenance fees. Good riddance!
You can see the full patent here: U.S. Patent No. 6,473,908
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