Marital idealization is defined as an interpersonal mode of self-deception whereby husbands and wives convey an exceedingly positive portrayal of their spouse and relationship (e.g., “My spouse has never made me angry”). For the Marriage and Health Study, we obtained responses from 119 long-wed couples at baseline, 1- and 2-years later ( M = 34 years married). We first computed and compared contemporaneous actor-partner interdependence models (APIMs) suggesting that marital satisfaction predicts marital idealization within and between spouses; the reverse APIM was not supported (i.e., marital idealization did not predict marital satisfaction). Yet our analyses suggest the question should be answered with longitudinal data. When reported contemporaneously, husbands’ marital satisfaction predicts marital idealization by their wives. The same cross-over effect is observed for wives—but not concomitantly, only in future. That is, marital satisfaction and idealization reported by wives predicts marital idealization reported by their husbands 2-years later.