Maybe the concept of a pair of pants came about in a scenario exactly like this…
I recently got a new pair of pants. I walk taller in them.
Old Timey Shopper: Ahoy good sir, might I acquire a pant today?
Shoppe Owner: Really? Just one pant? It looks like both of your pants are wearing thin, savvy?
Old Timey Shopper: Savvy. They are wearing quite thin. Probably caused by my bristly leg hairs that never cease from scraping the inside of each pant leg.
Shoppe Owner: (look of admiration)
Old Timey Shopper: Wait. How about I buy a pair of pants and just have my wife, Prudence, sew them together for me in a manly fashion? I think I might call them…(looks to friend) Jean! What should I call two pants I sew together?
Jean: Who me?
Old Timey Shopper: No, the other Jean.
Jean 2: I think you should call them…Franks.
Old Timey Shopper: I don’t know. That doesn’t seem to fit. Thanks Jean. And sorry first Jean — I hope I didn’t jostle you too badly.
Jean: (offers contemptuous gesture)
Shoppe Owner: (looking back to shopper) I think you are on to something there Levi. How is your papa, Mr. Strauss?
Old Timey Shopper: He was recently murdered by a posse — wranglers actually. From the west. Thanks for causing me to revisit that distressing event.
Shoppe Owner: You are welcome good sir. Now off with you. And your pair of pants too.