My reply to this is that I suspect that, like me, the kids sussed that the odds of a couple they approached being weird is low and the fact that they were a couple in itself makes the odds of them having ill intent much lower, too.
They may behave very, very differently if a lone man, or group of men, actively enticed them.
So your thin of the edge argument may not be true.
Cause let's be blunt it is men who are more likely to wish them harm. No argument about this please. It's the truth.
I sincerely mean it when I am sorry for those whose lives have been affected by an opposite sex couple (I imagine that the most likely scenario in the OP's case is that one is male the other female as this is more probable being that most people are heterosexual) working together to harm children but the Myra Hindley's and Rose West's of this world are extremely rare.
That's why they make the news. Whereas sadly we don't blink an eye about a lone man, or men, with ill intent.
Women may - and sadly do turn a blind eye to abuse-usually in a familial setting but actively collaborating to harm is extremely rare.
For these reasons, I think the OP is being hysterical in this instance and frankly needs to back off.
The story itself is full of holes anyway.