yes its this 'taken for granted' thing by people, its good to help out people but u should make it clear u are doing it as a favour people can start taking u for granted if they feel u are stuck with them & u are going nowhere, let people know u too can be upset speak your mind, I know your not looking for eternal thanks but its a low feeling to be taken for granted
As for Thai women well I have much experience of their kind believe me I speak from experience when I say that in general they are manipulative scheming selfish type who have scammed monies from friends of mine through lies & deceit , all the same I have one nice Thai friend -I used to steal knickers from her...