It was my friend’s turn to pay. But I offered

It was my friend’s turn to pay. But I offered
my credit card to cover the remainder after her $20
came up short. The cashier gave me the $20
to ring up the sale as credit card only. My friend insisted
I return the $20 to the cashier.

Epilogue: She saw me attempt this after she returned to our table. 😉

NOTE: An intellectually impaired adult friend and I take turns treating each other on our semi-monthly shared meals. She enjoys the equity of this arrangement, but keeps an eye out for any attempt at “cheating.”