More than half of US adults with a history of extramarital sex end up separated or divorced from the spouse they cheated on, according to Allen and Atkins’ analysis of 16,090 respondents in the General Social Survey (1991–2008). A history of extramarital sex raised the odds of being currently divorced and not remarried by a factor of 4.1 and separated by a factor of 5.8 relative to married, never-divorced individuals. We use that “more than half” prose summary — rounded to 55% — as the action-side headline, with the explicit caveat that this is a behavioural-dissolution proxy rather than an introspective regret measurement.
A peer-reviewed direct measurement of attitudinal regret tells the opposite story. Selterman, Joel and Dale’s 2023 study in Archives of Sexual Behavior surveyed three samples of Ashley Madison users (N≈810, 868, and 234 longitudinally) and found that participants “were highly satisfied with their affairs and expressed little moral regret.” On the direct “I regret having this affair” item on a five-point scale, mean scores sat near the disagreement end. That sample is, by construction, people who proactively sought affairs — the floor of any plausible regret estimate for the broader cheating population. The general- population rate sits somewhere between the Selterman attitudinal floor and the Allen and Atkins behavioural majority, and no survey lets us pin it down more precisely.
The inaction side is weaker. No published survey directly asks faithful spouses whether they regret not cheating. Karney and Bradbury’s 1995 review of 115 longitudinal marital studies (>45,000 marriages) documents how marital quality and stability change over time, but its abstract states no rate for how many spouses hold satisfaction steady, and no cited source measures regret among the faithful. We therefore treat the 15% inaction figure as an editorial coarse ceiling on any plausible inaction regret rather than a number read off a source. Its low magnitude is only loosely anchored to the one structural datum we can cite: Marín, Christensen and Atkins’ 2014 five-year follow-up of couple-therapy participants found that 77% of non-infidelity couples remained married, versus 57% of revealed-affair couples and 20% of secret-affair couples — a signal that abstaining from cheating does not on its own dissolve relationships.
Three different constructs hide inside the phrase “regretted the affair”: regretting the act, regretting being caught, and regretting having hurt the partner. None of the sources cited separates these cleanly, and the mix almost certainly shifts with disclosure status and marital survival. Clinical samples overrepresent distressed couples by selection. Commercial samples overrepresent affair-seekers. Nationally representative panels measure behaviour but not retrospective attitudes. Recall bias and social desirability inflate noise in every direction.
What this entry shows is directional, not precise. The behavioural evidence indicates that cheating destabilises relationships at high rates; the attitudinal evidence among self-selected affair-seekers is that they do not feel they did anything wrong. The road not taken — the spouse who resisted an opportunity and stayed — is essentially absent from the published record. Treat the 0.40 delta as a coarse upper bound on the action-over-inaction asymmetry, not as a substantiated percentage-point difference in introspective regret.