Hi all! 👋

I have a flight-related dilemma and could not find an answer anywhere and not sure what to do. Backstory: back in May I have purchased a rountrip flight with United for September from Spain to the States. I will be there one week for a conference. Recently, my plans have changed and it would be better for me to return to Austria instead of Spain, for an appointment (so I don't take another flight, from Spain to Austria). I have contacted United and to change the return flight would cost about $1000 and to cancel my return flight only, would cost $500. I have found another return flight that would take me to Austria, with Lufthansa and it flies out on the same day from the same airport. Can I just not show up for the United Flight and take the Lufthansa return flight instead? Would I risk anything or cause any issues, especially as I will be flying out from the same airport on the same day? Has anyone had this experience?

Happy to purchase another return ticket but really do not want to pay $500 just to cancel my return and another $500 just to buy another return. Anyone dealt with this before?

Thank you.