Hi Alexander, I read a wonderful article that you wrote about being in a relationship with a bisexual man. I am gay and married to a bisexual man, and I suspected as much before we started our relationship. So when he came out to me, it was no biggie because I had suspected as much, and by then I had fallen for him hook, line and sinker. We have known each other for 13 years now and got married in 2017. Something wonderful is/has happened; my niece, whom we had approached about becoming a surrogate mother for us, has decided to join us in a triad/throuple. My husband has been attracted to her since I introduced them several years ago, and it is only now that she has come on board fully and plans to join us in 2024. I am excited after the initial anxiety about losing him to her, but also know that what we are envisaging is/was next to impossible if not improbable. I am fully on board and prepared to share my husband with my own niece, whom she has also welcomed, fully aware that we will be sharing him. She has taken it in her stride and I am exhilarated because his sexuality will be taken care of, I retain my husband, and she gets to join us with a man who is absolutely loving, lovable, attentive, affectionate and will love both of us. I decided to take this leap of fate because I believe we could all be happy. Am I being unrealistic?
Hmm.
I think you will have bigger issues from sharing your husband with your sibling’s daughter. That seems likely to cause strife with relatives. What does your sibling, your niece’s mother, think?
That (not minor) detail aside, there is nothing wrong with the kind of relationship you are imagining. You can have a happy throuple with a woman, sure. Just not—in my opinion—with a biological relative.
Throuples (triads) can be tricky. Read this post for pointers on doing them well. My advice: do not date your own niece, and do not let your husband date your niece. Instead, work together to find a woman out there who is happy to share your husband with you.
From how I am reading your question, I assume you are not interested in having a sexual or romantic relationship with a woman—you just want your husband's hetero sex needs met. So I’m not sure I would call that relationship a triad or throuple. It would just be an open relationship in which your husband has another significant sexual partner, someone whom (I assume) you will not have a relationship with yourself.
For it to be a genuine triad or throuple, you would need to have a romantic connection with this third person as well, and that does not sound like what you want. You want your husband to have an extra partner who makes him happy, and you (and he) think that needs to be a woman, because he is bisexual. Fine.
Let him find a woman to play with who is not your biological relative. That will get messy, fast.
Love, Beastly