Aiyah, the parents of the guy really handle the things poorly by simply by already prejudicing over the TS parents. They think is expensive then sit down properly and talk to the in laws why put the son and future daughter in law in the middle? Asking a future husband and wife to take sides, are they trying to rip them apart? It just shown that they in-laws are not even using their old wise mind properly and not thinking about their son marriage at all. Imagine next time some argument happens again, the husband and wife will be forced to choose sides as well, that is simply the beginning of in-laws feuds which unfortunately will wreck marriages (i seen it in my family). In Asian families you don't only marry a person but you marry the whole family, failure to balance these two clans will results in huge amount of stress and cause a lot of arguments between husband and wife.
Think about it, it isn't just about the ping kam it is about how both families handle problems and their tolerance with each others. Plus, the future husband is a bit cowardly, pushing the future wife to choose between new in-laws and her own parents. I bet he won't side TS or stand up for her when she get into troubles with his mother in the future. Good luck girl!