Those are comments about a city, not a country, furthermore, Not one of those comments is untrue or O/T which I assume means over the top. I lived in SGN for years and all of those things and more personally happened to me.

Yes the toilets were out of action for 8 months. They did put out a sign saying under renovations but on the three or four occasions I spoke to the staff in the lounge they told me the toilets were closed due to a water leak that the airport was responsible to repair and simply would not. The proof is entering the toilets now and they have not been renovated in the slightest.

one example of cannot is requesting a particular seat at the Sattelite transfer counter to be told “cannot sir. Full already”. Then when I get on board that very seat is vacant and serviceable as I moved to it with the flight attendants permission. Malas!

It’s not technically a hidden city routing, unless one were to throw away the final segment to KUL and disembark at BKK.

However, it is “nested ticketing” - or whatever the term is - when someone tickets in a way that is clearly intended to circumvent airline price fences between different markets/length of stay, etc...

Because of this I would simply book the positioning flights on MH. TG would have no way of knowing, and no reason to even care why you ticketed out of KUL.

Many people I know who aren’t into flying and travel as much as I am look at me like I’m crazy for doing things like this. But, as someone who actually loves to fly, it’s a great excuse to take more flights, accrue more miles, and make a stopover in a city I enjoy.

I may be wrong but I thought the OP was looking at this as more than just one trip being a heavy user of TG through to Europe?

Apologies if I am wrong.

I did not advise throwing away any segment. I do not advocate or approve of hidden city ticketing.

What I suggest is buying a round trip positioning ticket, BKK-KUL-BKK. i.e. fly every single segment, and return to BKK on the MH ticket as well.

The reason for flying MH to KUL is that I wouldn�t want to advertise this choice of routing to TG. Plus MH is a perfectly good airline in my experience.

Thanks! I understand very well your advise.
However there are some downsides
- I would definitely have to go landside in KUL
- what can I do with the mileage for the MH ticket?
- to get convenience as well on the short haul flights, I would need to book biz on MH, while I could get lounge access and fast track on TG with Y

I wonder why you think I have to hide this towards TG? What can they do against me? I still do not understand the term "flag me"! What methods to they have or apply in such cases?

I cannot give any advice for certain. With U.S. carriers, for example, when I have bought two separate “nested” tickets to get lower fares on two consecutive trips, I have always used different airlines to avoid detection. In the worst cases of violating fare rules, an airline could terminate a frequent flyer account and possibly sue for fare difference, but that is “unlikely” unless one is a repeat offender.

Generally speaking, when you are doing something to circumvent fare rules, there is no risk if using separate airlines. If using the same airline and crediting the miles to the same account, there is some level of risk of detection. Whether or not, or at what point TG would act on something like that I have no idea.

If you do not do this all the time, it’s probably fine. It could even be logical for someone to buy a return ticket on TG if plans changed.

If you want to return from KUL on TG (or do a hidden city trick and and not take the last segment) as others have pointed out you should probably fly a different airline to KUL. You could then buy a return flight on TG for KUL-BKK after you have already flown the outbound portion of your ticket to Europe. Doing it this way makes your actions consistent with the explanation of a sudden change of plans. If you ticket far in advance, it’s obvious what your intentions are.