Most research has shown that sexual satisfaction in long-term relationships tends to decline over time. Studies showing the average trajectory, however, are limited by only assessing one slope. With longitudinal data from the Flourishing Families Project, Marital Instability Dataset, and the Iowa Youth and Families Project, we utilized growth mixture modeling to assess what trajectories of sexual satisfaction exist in midlife marriages. In the three samples (one individual, two dyadic), we found clear evidence for heterogeneous sexual satisfaction trajectories, for both wives and husbands. Through the datasets, we found some trajectories did decline over time. We also found stably high, stably medium, stably low, and some trajectories that showed an increase in sexual satisfaction over time. Overall, trajectories were similar for wives and husbands, though some classes had one partner with variability while the other was stable, some classes had trajectories with wives having higher sexual satisfaction than husbands, and some classes had trajectories with husbands having higher sexual satisfaction than wives. Demographic variables were not strong distinguishers of these differing trajectories. Both marital satisfaction and perceived marital stability trajectories (based on sexual satisfaction classes) generally had similar patterns to sexual satisfaction trajectories, with a few exceptions. Both marital satisfaction and perceived marital stability were less likely to significantly change over time, have discrepancies between wives and husbands, and have either low marital satisfaction or high perceived marital instability, even if sexual satisfaction was low. These data can help couples recognize various possibilities for sexual satisfaction over time, perhaps helping them to avoid cultural myths of inevitably declining sexual satisfaction.

大多数研究表明，长期关系中的性满意度往往会随着时间的推移而下降。然而，显示平均轨迹的研究仅限于评估一个坡度。利用来自繁荣家庭项目、婚姻不稳定数据集和爱荷华州青年和家庭项目的纵向数据，我们利用混合增长模型来评估中年婚姻中存在哪些性满意度轨迹。在三个样本（一个个体，两个二元对象）中，我们发现了妻子和丈夫的异质性满意度轨迹的明确证据。通过数据集，我们发现一些轨迹确实随着时间的推移而下降。我们还发现了稳定的高、稳定的中、稳定的低以及一些显示性满意度随时间增加的轨迹。总体，妻子和丈夫的轨迹相似，虽然有些班级有一个变化多端的伴侣，而另一个是稳​​定的，有些班级的轨迹是妻子的性满意度高于丈夫，有些班级的轨迹是丈夫的性满意度高于妻子。人口统计学变量并不是这些不同轨迹的有力区分因素。婚姻满意度和感知婚姻稳定性轨迹（基于性满意度等级）通常与性满意度轨迹具有相似的模式，只有少数例外。婚姻满意度和感知的婚姻稳定性都不太可能随时间发生显着变化，夫妻之间存在差异，婚姻满意度低或感知婚姻不稳定，即使性满意度很低。随着时间的推移，这些数据可以帮助夫妻认识到性满足的各种可能性，或许可以帮助他们避免性满足不可避免地下降的文化神话。