I know it may not have been started with clinton, and it's been around for a long time. But it was brought mainstream by his actions and was perpetuated by the media coverage of him and starr's investigation of him.
Which churches have you attended where you know of this to be true?
Personally, southern baptist. Friends who have attended catholic, church of God and Presbyterian churches report the exact same thing. The southern baptist churches I personally attended were both large and small - it happened in all of them.
Church going parents are usually the most clueless parents there are. One set of parents I know were so proud of the daughter and the job they did raising her. They wouldn't let her watch PG-13 movies and couldn't date. They talked endlessly how God gives parents the gift of wisdom and they regarded anything a childless person would say.
Ends up their daughter had given every just about every guy in her singles group a blowjob at one time or another and she wasn't the only one. Of course when they finally found out, the daughter "confessed her sin" and said that she had seen the errors of her way and was going to rededicate her life to Christ. The parents bought it hook, line and sinker.
Parents are often blind to what kids do and especially to what their own kids do.