Really, cuckokding is any arrangement where one spouse has sex with another person, but the other spouse is ecpected to or simply prefers to remain faithful. If both spouses are having sex with others, it is simply an open relationship. That imbalance in sexual indulgence or freedom is what makes it cuckolding. While I suppose that it is possible to make any level of commitment into a cuckolding dynamic, it doesn’t make sense to me as real except within marriage, which has the normative quality of sexual exclusivity between the spouses. In cuckolding, one spouse is set free from that expectation. That may mean that the sexual exclusivity is dispensed with for the cuckolding spouse, or it may mean that the exclusivity is transfered from the spousal relationship to the extramarital relationship. It may or may not involve humiliation or servitude for the cuckold. The main thing is that it is done with the consent of both spouses, or else it is simply infidelity. I think that the consent really should be enthusiastic, or evrn with the cuckold’s knowledge and tolerance of cuckolding, it is infidelity.
I think that you have to figure out what turns you on about this, and discuss thet with your fiancee. You need to know, before the wedding, what she thinks of it, and whether it is a real option, or if she’s comfortable with it being an option for her. That way, you can go into the marriage with that understanding. You also need to decide whether you want the marriage if she is adamant against whatever version of cuckolding you are interested in.
However, you really need to be clear about what marriage is to you and to her. If it is about the relationship between the two of you, you may want to be married and monogamous for several years, to bond with each other in the way that only years of marriage can do, and then see if you are still interested. Everything I’ve read indicates that the marital bond must be string and healthy if cuckolding is to be an enhancement, rather than a destructive element. Be very sober in your judgment. If you know that you are okay with or hoping that your romantic relationship will get sidelined or lost altogether, then by all means, find a bull to inseminate her on your wedding night before you consummate the marriage, so that she will never think she has to put you first sexually. Otherwise, if you want the love between you to always be the ground and ultimate focus of your sex lives, even if she excludes you sexually for a time, then give your marriage a chance to grow solid. My two cents.