'That is correct but there are twinks- gay guys- in Pattaya and Bangkok. Why not Chiang Mai? Or so it seems.'

Probably because the bamboo telegraph has been put on steroids by the advent of mobile telephony, from which they can probably deduce that Bangers pays top dollar but the business is not always red hot, whereas a cutie in Pattaya can get his sphincter stretched three or four times a night. Chiang Mai on the other hand, tends not to deliver either..