More Likely to Cheat at Ovulation

How A Woman Feels Midcycle could depend on her man’s testosterone:

Women with low-testosterone men are more critical of their partners now—as if their standards are raised during the 2-3 days around ovulation.

Women partnered with low-testosterone men are more likely to cheat now than at other times in cycle.

Women look less for partnership and more for good genes. They are more likely than usual to sleep with someone they don’t care about.
-Larson et al (2012)

Detail from “La Confidence”
by Edmond Aman-Jean.
Text from Dangerous Liaisons by Pierre Laclos.

Donald Symons explains why extramarital sexual desire is adaptive for women:

"Sexual intercourse with men other than her husband may benefit her in three ways: (1) She may exchange sex for other goods and services. (2) She may ... be impregnated by a fitter man than her husband [which] may pay off reproductively. (3) She may be able to use sexual intercourse to divest herself of her present husband and acquire a better one.”