I married a woman with a daughter from a previous marriage.

She never touches her salary; all household expenses are paid by me.
Once, I was short on money and asked if she could contribute a little,
She said: My money is saved for my daughter's future.
I said, but she's my daughter too,
She said: It's different.
One day, her daughter asked me: Dad, Mom said you're not my real dad, so you can't scold me.
I said: That's right, but I paid for your tuition.
She hesitated, then ran back to ask her mom.
That evening, her mom questioned me: Why did you tell the kid that?
I said: I was just teaching her to keep track of her expenses.
She slammed the door and left,
Her daughter quietly counted her tuition fees,
Then copied each one into her notebook,
Finally, she tucked her mom's ex-husband's remittance slip, sent back in the last page.