So you are like many around the world who are dating a Thai lady and you are not sure of some of the ins and outs?
There are a few little tips that have helped me, and most I have learnt on the way either the hard way or the easy way but if you know what you are getting into before you take that extra step then life will be easier.
Calling home - Thai women love to call home and chat alot with family... let it be and don't say a word, just enjoy the alone time for these chats can go on for hours. Normally to more than one person. I think it has alot to do with the close family values Thai people in general have. Just accept it.
Money - There are two types of Thai, ones that think everything evolves around money, and others who are very money savvy and down to earth thinking that money is not everything. I think I am lucky with my now wife being the later type who is very smart with money matters and not hungry for every little bit of green. I have heard and seen stories where Thai women have needed money for a "family emergency" and received a great deal of money from boyfriends to help out the family back home. Be careful of these situations. Many back in Thailand will be asking your girlfriend or wife for money, but look after yourselves first and make that point clear in your relationship.
Spicy food - Thai women will get grumpy if they don't eat something spicy every couple of days. They will think that your western food, no matter how good a cook you are does no have any taste unless drowned in chilli. I often joked about developing a spicy tea flavoured drink with is like a mood adjuster for Thai women. I'm still working on that with my wife... she never wants to drink it.
Som Tum - This is a traditional dish made from a mixture of local ingredients and my wife uses carrots, tomatoes, noodles, chillies, pla (which looks like black sand), and fermented baby crabs. It looks a bit weird for most westerners but I have been assured it is really nice. It is super spicy and the smell lingers for a while. Just get used to it and try a real one at your own risk.
Gossip - As with most cultures from different countries, when someone moves to another country there is always groups of friends that all know different people and there are strong communities from different countries. Thais especially like to know everyone's business and tend to talk between themselves about what is going on in other peoples lives. Just be aware of this and if there is something that you don't want others to know, play your cards close to your chest and don't talk about it. If you do, then be prepared for everyone to know very soon. This is also relevant when it comes to getting advice on immigration matters and study options for your partner to stay in the country of your choice. Everyone knows someone that has been there and done it. Get solid and professional advice and don't listen to the community.
Thats all for now, I will try to elaborate on more as time goes by.