As some here said, fantasies change over time.
My current ultimate fantasy is that prior to our wedding she found a boyfriend we are compatible enough with to be a live in boyfriend.
We arrive at our wedding venue a week early and have a cuckold wedding ceremony, like the ones you can find online, with a kink friendly officiant. The wedding party would be me, her, our bull and her maid of honor who would be in the know.
During the ceremony, she would be wearing the garter and leggings from this picture and the lace top from the other, and white panties. The bull would be in a banana hammock to show off.
The maid of honor would be wearing something provocative but not lingerie, something like a super short tight fitting dress.
My fiancé would lead me down the aisle on all fours, with a collar and leash on. I would be be in a matching outfit to her except also with ball gag, chastity device (with spikes like the pick here
The hyperlink is visible to registered members only! and a small butt plug.
To signify my commitment I fluff our bull to get him hard while the ceremony proceeds. At the right time, I remove my fiancé's panties and guide our bull into her to seal the ceremony.
The next week he is the best man at the regular wedding but she is late. I am still in the same chastity device. Our bull goes to look for her and the maid of honor and finds them. Prior to the actual ceremony, her filled her full of cum and she wore a plug to keep it in until the ceremony.
When he goes to find her she removes the plug. She sucks him off right before she comes to the aisle with his cum running down her leg under the dress.
When we kiss to seal the ceremony, she pushes his cum into my mouth from when she sucked him off.
That night, the 4 of us (me, wife, bull and maid of honor) retire to the bridal suite and I and and dressed in a French maid outfit, fully sissified, and serve the three of them all night. My maid outfit looks like the following.
Our maid of honor spends the night photographing them for our wedding album as the consummate the marriage. When she isn't taking pictures, she has the option of fucking my ass with a strap on the same size as our bull, or receiving oral from me as I am required to serve all. The 3 of them humiliate me through out the night about my small useless dicklette.
We certify the marriage with the state the cuckold ceremony.
During the honeymoon, our bull, my wife and I all go on vacation. We have rooms with a shared door so I can hear them fuck all the time. When we do leave the room, we present ourselves as a couple (them) and their single sissy friend looking for some fun . The spend every evening trying to get me a bi boyfriend while they fuck like rabbits in the room next door.
When we fly back, we return to our separate homes. We look for a larger place that can support two separate hoses should we need it. We (all 3 ) build a large duplex with no split between the units. They take one master and I in the other with just audio piped in to my room.
My job is still to serve them, provide services when she is feeling ill, clean her when he's done with her. My job are the domestic duties (cooking, cleaning, etc), his are to ensure my wife is well serviced, and hers are to walk around looking her best, and mercilessly teasing my cock. (Still in chastity, just w/o spikes for non special ceremonies).
Our maid of honor still comes by when she wants to humiliate me more.
Edited:
forgot to add that part of her job looking her best is to always be manicured, pedicured, have laser hair removal all over (according to her bull) and regularly get a temporary tattoo of whatever her bull wants. When they go out, they are the couple and I'm a friend/brother or (depending on what they want) sister. She wears what he wants her to, not matter how short or see through. Same with me when I'm in sissy mode.
