Here are the rules, at least for the high-class guys:
…Martinez has "rules of engagement": The target must not
be drunk, there must be no touching, and the relative
attractiveness of the trapper to the target must be equal.
"It’s got to be a fair test," he explains. "So we make sure
that we don’t set a very attractive honey trapper on a not so
attractive target, and vice versa."
"The customer needs a fair answer to the question of
whether their husband or girlfriend is loyal."
So those who fail an "unfair" test count as loyal? But since eighty percent of all those approached fail, maybe the point is simply to drive home the decisive nature of the infidelity. A related question is whether the customer (usually the spouse) wants the target to pass or fail the test. Furthermore what does the customer want to think about the customer’s own motives? Here is the full story, and thanks to Jeffrey Ely for the pointer.