Straying somewhat from the original question,but since you ask, Viktoria:
I don't consider it appropriate to issue value judgements about another person based on their sex life, as long as that sex life is between consenting adults.
I believe you can be a DECENT human being by caring for the world around you and those in it and by working to help people. Who you have sex with (as long as it's another consenting adult) doesn't come into that. You could be totally monogamous with your partner, yet be the most horrible selfish cruel person in other respects - that would not make you "decent".
The separation between what you term "decent" women and what you, or others, term "fallen women", allows a mindset which devalues women who have sex outside tightly societally defined boundaries, and results in the sort of abuses seen in situations such as the magdalene laundries in Ireland to give just one example. It also lets men off the hook - because it is only ever the woma who is held responsible! If you feel it's appropriate to use "slutty" epithets for female sex workers, where are the similar terms for men who use prostitutes? This more than any is a customer-driven trade -- without clients, there would be no prostitution! Why blame the women?
Language is important. Using terms like this easily leads to the conclusion that some people are less worthy of help, or deserve punishment for their "sins" -- even that their children, totally through no doing of their own, are equally or even more undeserving. Again I say, look at the magdalene laundries for recent examples of where this leads.
I don't expect for one moment that I will have swayed your opinion with this post, Viktoria, though I find attitudes like this narrow and unforgiving. You'll probably be glad to hear that I don't plan on adding further to this line of conversation as I think I've said everything that I can say.