Most foreigners who visit or live in Thailand spend most of their time in the tiny percentage of the country which farang-oriented prostitutes are attracted to, a naturally select population. But many do not. From my viewpoint, those steeped in the farang prostitution areas are best staying in these areas, and going thru the shorttime adventures with bargirls and freelancers ad infinitum, and persisting in their cynical illusions of denial, because these farangs would not be happy with (nor faithful to) a mainstream Thai girl for very long, and neither would a mainstream Thai lady be happy with them. If you pursue a mainstream Thai lady, then you should be as faithful to her as she is to you. Otherwise, you will have fewer problems if you just stick to the other side of town, because prostitutes are used to providing service and then making a break after receiving the money without any emotional drama (except happiness to get money), so it stays simple and clean (bullshit aside).
Indeed, most farang males who work in offices take little interest in co-workers, and spend much more time at pubs with their friends and developing mutual flash-in-the-pan relationships with the outgoing and skilled Thai ladies of entertainment venues, because there are so many lovely ladies among them who are easy to chat up, outgoing and willing to move into a sexual liaison in very short time when an opportunity comes within range, especially if the man fits certain criteria such as being dressed as if they have money, clean, cheerful and easygoing.
Do not treat your coworkers or employees as if they are similar to bargirls. Just like in your own country, Thailand has different kinds of people in different walks of life.