Flying United on tickets, have a question
 

Taking the family to Europe this summer, and bought tickets.

We are traveling IAD-AMS going over, and the return flight is AMS-MUC-IAD.

Question: The leg from AMS-MUC is on Lufthansa CityLine and then we connect back onto a United mainline. We don't want to go back to AMS, and would rather just end our vacation in MUC and then go home. If we don't check-in @AMS will we loose our seats from MUC? Or can we just show in MUC and go home.

Appreciate any info... feel free to PM as well.

Yes, when you no show a segment your reservation and seats are cancelled. This is true with all carriers. I would call reservations and see if they will alter your ticket. There may be a fare change associated so see if it is worth it for you to change. Definitely don't just no show and then appear in MUC.

This rule was invoked by the airlines when passengers were buying tickets say from NYC to COS with a stopover DEN. Often the ticket to COS was much cheaper than DEN. So they would get off and on in DEN where they really wanted to go. The airlines broke the code and ended that loophole. If I remember correctly NWA was the first airline to do this and rest followed quickly.