For those thinking permissive sexuality leads to societal problems compare two countries: The Netherlands with a very open attitude towards sex and the United States.
Divorce rate: US 2.9/1000 vs. Netherlands of 1.8/1000
Suicide: US 23.7/100K vs Netherlands 9.6/100K
Single parent household: US 23% vs Netherlands 16%
Instead of railing against the evils of extramarital sex, maybe we should spend more energy on birth control, family planning and sexual education/awareness.
Divorce rate
Suicide rate
Single parent rate