The practical demands of wartime changed social customs. People enjoyed far greater social freedom than before, with more opportunities to meet members of the opposite sex, and a sense that normal rules did not apply in such dangerous times. "Live for today you might not be here tomorrow" was a phrase often heard.
The drawback to such new opportunities was the increase in numbers illegitimate children and of people with venereal disease. Being, or having an illegitimate child were socially unacceptable then, but even so, there was a huge increase in the number of children born to single mothers during the war.