I lived in Bangkok for 20 years. In the early years I was doing the bar girl thing all the time. However, during the last 5 years I hardly bothered at all. I became very cynical about that stuff, my thoughts:
It's too 'easy' to do, there's no 'value' to it.
Very often it was evident from her demeanour that she wasn't really 'into' what she was doing.
I would rather keep 3,000 Baht in my pocket.
Over the years I had a few Thai ladies who had ordinary jobs as girlfriends.I believe that many people who haven't spent much time in Thailand aren't aware that this is possible, partly because all they ever see is touristy-Thailand, where bar girls are 'everywhere'.