Junie Gray, a woman from Austin, Texas, told me she doubts she could find someone who “understands, supports, and loves” her like her husband does. Because people today wait longer than previous generations to get married, many simply might be selecting the actual right person for them. There’s no need to cheat when your spouse is your best friend, your soulmate, your “everything.” There’s no “one that got away”; you caught him. It just took you until you were 36 to do so.

As the Johns Hopkins University sociologist Andrew Cherlin put it to me, “over the past few decades, marriage has become more selective.” Today, the people most likely to have lasting marriages are those who have gone to college. And college graduates seem “more committed to each other and to the marriage,” Cherlin said. He pointed out that the divorce rate has gone down significantly for college-educated couples, but not for couples in which neither person has a college education.

I heard from a lot of people who prudently dated their partners for several years before getting married, then waited still more years before having children, just in case. There’s less societal browbeating these days to move faster. “There isn’t pressure to be in relationships like there used to be, so people are less likely to settle for a bad partner,” says Skylar Dallmeyer-Drennen, an energy consultant in Washington, D.C. “Why put up with a cheater if no one needs you to be dating?”

This trend is intertwined with what my colleague Kate Julian described as “the sex recession.” Young people today have less sex in general, so it follows that they are likely having less of it extramaritally, too. “We’re living in an astonishingly sexless age,” Wolfinger told me.

Of course, we are also living in the midst of a sexual-harassment crisis. But a number of #MeToo offenses seem to be perpetrated by older men, some of whom blame changing mores for their alleged transgressions. Though there are also stories of young men who don’t know where to draw the line between friendship and romance, experts say that in general, young people tend to be more supportive of gender equality. Cheating, meanwhile, can feel deeply inequitable. Infidelity sometimes gets lumped in with other types of harm against women: Several of the entries on the “shitty media men” list that was circulated a few years ago involved allegations of affairs.

Or maybe it’s something about being Millennial, rather than a married Millennial, that deters two-timing. A few people who responded to my Twitter inquiry suggested that maybe Millennials in general are still young and idealistic. My generation wants jobs with a purpose, and we want relationships that feel purposeful, too. Or, as a Gen X friend of mine speculated, perhaps Millennials are terrified of breaking rules. We’re so preoccupied with getting recommendation letters and maintaining our brands that we would never sully ourselves with something so carnal and impulsive as infidelity. (My friend asked to remain nameless, because he didn’t want to seem like he was justifying adultery.)