To find that sort of behavior you have to be where it is happening.
Any man who has been in Bangkok knows where the red light districts and can easily avoid them.
Obviously you didn't and as far as being propositioned in Big C walking through shopping malls and restaurants go Thai women simply are not that forward and even prostitutes are different people when not working. You are living in a dream world and it's not Thailand...Prostitutes out shopping are out shopping and unless you approach them they would never approach you anywhere there is cameras and security guards. They would be thrown out immediately and lose face
I have been in hundreds of places with friends and not a prostitute in sight so obviously your idea of a nice place for a drink lies between Cowboy Patpong and Nana.
But then I have an education and smart enough to know where to go. You obviously do not.
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regards
1 very angry Thai lady