- Intimate exposure to large sample group throughout the US.
- Ability, via internet, to dialog with many different sub-categories of people on the subject. These categories include age, race, and religion.
- Plus my advantage of not always being a swinger, and therefore having a solid understanding of the psyche of both groups, allows me to better evaluate the subject.

Bottom line, if you need a double-blind study from a non-biased team of experts to accept the idea that couples without jealousy in their relationship (swingers) will have a better chance of staying together than those who more often do (monogamous partners), then I am not smart enough to help you understand the lifestyle any better.

Do you have any references to support this? Anecdotal reports are not enough, since they may be affected by selection bias.

1) While it may be true that a small portion of the swinger community is involved for reasons not totally clear to both parties (i.e. woman wants to be with other men, so she convinces husband to swing), the ultimate reasons for an open relationship of this nature are vast and loosely connected. However, lifetime partners who participate in the swinging lifestyle tend to share a bond that is more fulfilling and stronger than most “vanilla” couples. This is because they transcend the issues of jealousy and ownership of each other, and instead give to one another the gift of freedom to choose.
2) MF, FF, and MM who open their relationship to others should be the only true definition of “swingers” for the purpose of studying this lifestyle. Single males and females are simply components with individual motivations not necessarily connected to “swinging.”
3) Trends, as you have called it, are not so easily measured by even studying a large population. This is because each individual has their own preferences, each couple has their agreed upon limits, and each group has their own collective standards. Plus, if you only look back 25 years, then your conclusions would be similarly misguided as if you were to take the weather patterns of the past 25 years to define global climate patterns.
4) To refer to women who enjoy swinging and sex with multiple partners as “slutty” demonstrates a fundamental misunderstanding of human nature and known concepts of evolutionary-based sexual behaviors. As for a woman that enjoys multiple men at the same time, I wonder if this is as hard to understand as a man who would enjoy multiple women at the same time. One simple psychological explanation would be the need (and erotic desire) for attention.
5) To a much less important point, the prices listed above are not common. Females tend to have free admission or a relatively low price, MF couples are charged a cost relative to the party venue, and single males are charged a premium. This is because most females of a swinging couple are bisexual and therefore both members of the couple can be sexually attracted to, and share, the same female (which is not nearly as common with single males.)

I hope these points are helpful in your understanding of the swinging lifestyle. While the choice to have an open relationship may not be as common as monogamy, it definitely is common enough to command the respect of others as a lifestyle that is healthy and fulfilling. In the future please consider this for all walks of life: Conviction without knowledge is the most dangerous form of ignorance.

I’ve seen similar sorts of arrangements where the implicit price for women was negative.

Tobias: You know, Lindsay, as a therapist, I have advised…a number of couples to explore an open relationship where the couple remains emotionally committed, but free to explore extra-marital encounters.
Lindsay: Well, did it work for those people?
Tobias: No, it never does. I mean, these people somehow delude themselves into thinking it might, but… but it might work for us.

Also the age-distribution of swingers has changed during the last decades (iirc, don’t have a source) which may also lead to the changes observed.

The medium-age in the italian study was 40…