Said to thank someone and promising to do something for them in the future

If you hadn't driven me to the airport in a hurry, I would have missed my flight. Thanks, and remember: my turn next time!

Se non mi avessi accompagnato tu all'aeroporto in tutta fretta, avrei perso l'aereo. Grazie, e a buon rendere!

 “Can I get you a coffee?” “Thanks, but I wouldn't…” “Don't worry, today it's on me” “Thank you. My turn next time!”

“Posso offrirti un caffè?” “Grazie, ma non vorrei…” “Non preoccuparti, oggi offro io!” “Grazie, a buon rendere!”