Taitai,
It is not yr nature to look for affairs, but being emotionally depleted will put you in a vulnerable position for affairs. If a guy treats you really nice, makes you feel loved again, would you succumb to temptation? It is hard to tell, cos human emotions are hard to predict. No matter what, women lose out in affairs. We get emotionally involved easily, even we may tell ourselves to be detached. Like what passila has mentioned, to keep yrself occupied. It can be a small business or pursuing yr own hobbies etc. It is all abt diverting yr attention away from yr sadness, loneliness etc.
I feel sad to hear abt yr friends' situation and what their kids has said to them, it just goes to show how selfish their kids are. But, hv you ever thought why the kids are like that? If the parents hv been putting up an act for such a long time, all for the sake of "face", what do you think this action teaches the kids? When the kids are grown up, those who are selfish will say might as well continue the act since you hv been doing it for so long, or if the mother has always nurture the kids with good moral values, and they can empathize what the mum went through, they would encourage her to leave the marriage as they want her to be happy.
My two kids are different in character, my elder gal has seen me cried, being sad and angry due to my husband in the past. Sometimes, she will tell me to be happy when I told her I may leave her daddy when the time comes, of course she does not know what may happen after a divorce. Nurturing yr kids now is very important if you want them to grow up as responsible, filial, kind adults. How many kids are able to empathize with what their parents go through to earn a living when everything is well provided for them without them hving to struggle when they do not go through hardship at a young age? My advice to you is to teach and guide yr kids well, and not to just provide happiness for them at yr expense of yr emotional health. I know most kids come from a family of working parents and most of them are well provided materially, that they don't treasure the things that their parents hv bought for them. This is what I hv learnt from my gal when she was in P1 last year, her friends gave her toys that they hv grown tired of, and I told her to give it back. At the end of the day, it is yr life and only you can make a difference in your future. It doesn't hv to be so bleak. Take care.