[TainuibeFaimb]

(without opening my mouth, cuz that would give me away) This is the important point. Although you are racially Thai, given your parentage, unless you hold a Thai passport, the exception does not apply to you. Hence your comment about keeping your mouth shut. Most farang are guests in the kingdom, no matter how long they stay. If a farang has applied for and received Thai nationality, the exception would apply and he or she would pay the Thai price. Other than some surface judgments made on the part of those collecting the money, race really doesn't play a major part in the decision. Such assumptions are no different than assuming every old farang with a Thai wife is married to a former bar girl, or that a man with an earring must be gay. Sometimes these assumptions are true, and sometimes they are not. The point is that Thailand makes money from tourism, and the idea is that tourists can afford it if they want the experience.