This is going to be based on my experiences in the last 40 years with three women who have cucked me plus the people we have known over that time. I have the most knowledge of my wife of the last 25 years. Many cuckold relationships start the same and reach a lot of the same forks-in-road with all kinds of different outcomes.
It usually starts with a married couple wanting to "push the boundaries" a bit regarding relations with other people and sex. The husband usually is the instigator having to convince the wife to at least dress more provocatively and maybe do a little flirting. It usually doesn't stay at flirting long and one or both partners want to up the anti top full on fucking. Here is the first decision. Are you looking for activity for husband and wife, or just the wife. If it's the first, people usually go into swinging. If it's the second, it usually goes directly to some form of cuckoldry. In my cases it always started with swinging. The thing is, the women are always going to attract more attention than there partners. The wives can always draw more, younger, and better looking guys because there are so many fewer women willing to fuck around than men. Maybe 1,000 to 1 or something. If the wife likes that attention, as my three have, they want to be fucked by a lot of the young, great looking guys even if they don't provide a woman for swinging.
Then the next negotiation begins. The wife says she will go on a swinging date with the husband if she can have a date with one of the many men who are after her. The husband says sure. The next decision is how much involvement does the husband have in her dates. Is it always a threesome or can she go alone sometimes, always, or never? Whatever is decided can always be changed by the wife because, as the husband is now starting to realize, the wife has all the power in the situation. Soon the wife will want two and then three dates for each swinging activity because, as she will soon point out, she only swings to keep him happy. She doesn't "want to fuck her husband" but does it "for you". Soon she will "really want to go on some or all dates alone or she just cant see how she can keep swinging". Before too long there is no more swinging and the wife is going on dates when she pleases. The agreed length of the dates soon changes as well. In my case it went from evenings to overnights to a week at HedoII with him when she couldn't find time to go with me "this year".
Also, in my experience, all other rules are subject to change. For instance, it has been "condoms only" at the start with all of my three. This lasts until the wife finds one guy she "really likes" and wants to go bareback with him. Or, as in my case" the wife has decided to fuck exclusively black men and doesn't want to disrespect them by asking for a condom which "black guys don't like". The husband says sure because by now he suspects she will do it anyway and has lost the nerve to challenge her. The husband takes a big step into cuckoldry here because there is a big difference between having another man fuck your wife and having another man or men actually cum inside your wife. In all societies, this act is a very strong mark of possession by the other man or men. The thought of men mixing their DNA with your wife's is very sobering, even if you don't think she can get pregnant. The fact that she wants his seed inside her is enough let the husband know where he stands. So, if the husband ever gets with another woman, does he have to wear one? "Yes" she says and he wont challenge her on that either because "hell, it probably wont happen anyway". Then one night the gradual shift of power from husband to wife becomes a lot more steep when she says "you know, just for fun, for a little while why don't you wear a condom when you fuck me". She explains that she wants to see "what it would be like" to have only the BFs seed inside her. The husband's pattern is already set by now and he says sure. After a few years of this rule the wife decides she will let the husband inside her bare back, if he will get a vasectomy . "We are done having youngren anyway" she explains. This happened to me three years ago. Five months ago my wife explained to me that she was going to "settle down" to four guys(two middle aged black men who are brothers and the two misters of one of them) to see regularly and stop fucking around because it was "safer". Four months ago she told me she was going off the birth control pill because it was unsafe at her age (45) and because she wouldn't get pregnant anyway, at her age. The funny thing is that, since she went off the pill, the talk among her and her lovers has been about nothing else but "knocking her up". She will say things to me like "you can shoot blanks in me if you want, it doesn't matter".
I must love this stuff, right? I have done it three times!