My date used a coupon for our dinner and kept the cash difference

We agreed to split the bill.

Total was $80, so I gave her $40 because she said she’d pay by card.

Then she used a 50% discount voucher.

Actual bill: $40.

She still kept my $40.

When I pointed it out, she said the coupon belonged to her, so the savings belonged to her.

I think I just attended a finance seminar.