Acting on their fantasies was as good or better than expected & it improved relationships, especially those already in good relationships, people with a higher sex drive & thrill-seeking tendencies, & people who adapt to stress & uncertainty

Seven Fascinating Facts About Sexual Fantasies. Justin J Lehmiller. Psychology Today, Oct 01, 2018. https://www.psychologytoday.com/intl/blog/the-myths-sex/201810/seven-fascinating-facts-about-sexual-fantasies

3.) While threesomes were the most popular fantasy, they were also the fantasy that was least likely to turn out well when people acted on it. This is probably due, in part, to the fact that different people prefer different threesome scenarios, which may make it challenging for everyone to get what they want. However, it’s probably also due to the fact that most people don’t have a script for how a threesome should go, which means that many people end up in a multi-partner situation with a lot of uncertainty about who should be doing what with whom and when.

7.) For the most part, people who acted on their favorite sex fantasies reported that things turned out well. The numbers varied a bit depending on what it is that they did—and, as mentioned above, group sex was the least likely fantasy to turn out well. Overall, though, most people said that acting on their fantasies was at least as good or better than expected and that it improved their relationship. However, some people were more likely to have positive experiences than others, and that included people who were already in good relationships to start with, people with a higher sex drive and thrill-seeking tendencies, and people who are good at adapting to stress and uncertainty, meaning people who are low in the personality trait of neuroticism.