[M4F] Sibling marriage in an ancient world

Male playing age 26 looking for a female to play age 20-25 for a brother-sister incest roleplay. The roleplay will be a bit longer-term on Reddit Chat or Discord and takes place in a fictional ancient society setting in a tropical climate (such as around beautiful beaches, deserts, and jungles), where incest marriages are culturally and socially accepted, with inspirations from real ancient societies.

In our society there is a rule that by the time a person reaches a certain age, he or she must be married if they aren't already. If a man isn't married by the age of 26 and doesn't have any particular woman to marry, he is to be married to his sister, if he has one and she isn't already married. Likewise if a woman isn't married by the age of 25 and doesn't have any particular man to marry she is to be married to her brother, if she has one and he isn't already married.
The idea is that it is someone they already know and thus don't have to spend time to find and get to know someone else, and they should already get along, and should be able to be happy together. It is not considered a last option and that there isn't anyone else to marry, it is considered an option that might be good to have. That no matter what happens, in that case you always have someone who should be good for you to marry.

The setting is detailed and I'm looking for someone who likes a lot of buildup, details, and descriptive posts. It's not necessary for replies to be a whole page or so, but at least generally longer than a line or two. The idea is more towards roleplay and story and building romance, not just sex. Sex is a part of it and is important, but is not the focus, and doesn't happen until later. If you're looking for sex quickly this isn't the roleplay for you, but if you're fine with things taking some time as love and the relationship develop and we become a couple there will eventually be lovemaking. It won't drag along forever before there's any sex, but it should take some time.

Sex shouldn't happen until after the wedding and that makes the most sense in the setting, and with this being longer-term it shouldn't just be once. That just goes into married life and several times of making love, and pregnancy and having children. Time will be moved along as needed in our life as a married couple. Before the wedding there can of course be kissing and generally being more affectionate towards each other, and possibly even more intimate things, but no actual sex until later.

As for kinks and limits there's no specific list, but things should fit into the roleplay. It's more about love and becoming a couple so sex would be more fitting in with that rather than darker stuff like rape, pain, and degradation. With the marriage theme it would later include pregnancy and having children so you should obviously be fine with that.

Our looks in the roleplay are typical attractive things such as both being fit, me being athletic, you having long hair, me having a large cock and you having large boobs, both of us being shaved, and things like that. It will have at least some mention in the roleplay.

If a person doesn't have someone to marry when they reach the age of 26 or 25 that is considered very strange and they should find someone to marry as soon as possible.
A situation like this usually doesn't happen, and a brother and sister can marry each other if they want to, so some do so anyway. Some marry each other for convenience, since it means they don't have to think about finding someone. It is not a usual type of marriage, but many brothers and sisters are happily married. Of course not everyone gets along with their brother or sister, so having to get married can be a problem.

Now I have recently reached the age of 26, and since neither of us have someone we are supposed to get married to each other. For whatever reason we haven't met someone else to marry. The wedding is supposed to happen in a few months, giving us some time in which we are supposed to get used to each other as a couple.
We do get along well, but we didn't expect to be married to each other. Maybe we are fine with it, or maybe only one of us is fine with it. Perhaps both or one of us wanted us to get married anyway, or at least make it look like we wanted to. Perhaps we can find reasons for why it would be a good idea for us to marry each other. Maybe we for one reason or another don't do anything more than perhaps sleep in the same bed even after several months of being married, until we talk about that we really are husband and wife now. Just some suggestions, and we'll decide how we want to do and how our starting attitudes are. Others might have different reactions about it, and several think we would make a good husband and wife together, including our parents. In any case we will be used to each other and be happy together.

The roleplay starts some time after we have been told that we are to get married, with plenty of buildup before the sex. We can advance time at different points so it can take place before the wedding, during the wedding, and after the wedding. Sex will not be until after the wedding. Of course we can do other things as we get more used to each other as a couple, such as kissing and being more affectionate towards each other.

We can decide for ourselves how our daily lives are. I am a reserve soldier, meaning I am only called in to duty when needed. My daily life is otherwise to work with other men wherever needed, such as helping with building something, making tools, farming, fishing, and the like. You can decide what you do and how your daily life is.
We live in a walled city, me in my home, and you in yours. The city is close to the sea and has a harbor, and has a beach nearby. The city has a desert in one direction to the side of it and a jungle in the other direction on the other side, and islands close to the coast, with settlements on some of them. Ferries connect the islands with the mainland. The beach and parts of the desert and jungle close to the beach are often visited by citizens for recreation. Other than that the city has what can be expected, with markets, stores, taverns, cultural buildings, and so on. Maybe you have ideas you would like to add as well.

As you have probably understood this roleplay is more intended to be light in tone and towards romance and becoming a happy couple with sex later, but that doesn't mean there can never be any problem cropping up. There could be some problem or difficulty that we have to handle but overall it should be a friendly and enjoyable roleplay.

If you think this roleplay is for you then we'll talk more about the setting and go through the worldbuilding together to make it into a place we both can enjoy.