When did the proud of virginity and on condition of marriage and jeolousy die out?

I never sean any western society. My experience is from books literature and movies, The western society and some ex commuist countries were someday respecting virginity and put the faithfulness to spouse in a holly atitude. even the sea clothes were (in 20ths)covering body more than now if they still cover any thing. The movies and media show husbands and wifes who behave normally toward cheating. " she:sorry dear i felt lonely and it was a party and we drunk much i will never do it again. he: promise?". even many cases where people marry with 4 children. when did this starts and why. is it good or bad and how. is it a benifiet or a price paid for the modern life style