I've identified as polyamorous for many years, and do indeed love many. But even if I love many - you know, the soul thrilling, intimate, vulnerable kind - I have recognised that sexually, I (eventually) prefer exclusivity. I've noticed that my multiple relationships are often a transition from one sexually exclusive one to another (with an overlap of up to five years). It's okay by me if those I love have several relationships (sexual or otherwise), but sooner or later when I go sexually 'deep' with one person, I am interested in little physical action with anyone else. This has happened three times now, each time resulting in heartbreak.
I feel like I have betrayed my loved ones because I cannot sustain multiple sexual relationships with them. Still, I cannot be monogamous because many of my relationships are far deeper than traditional monogamy allows. I don't want to be a serial monogamist, because some of the best times in our relationships have been in the overlap. Help!????????
Thank for opening this can of worms, because I feel it is a very common occurrence. What is uncommon, is what you have done - which is to let go of society assumption and identify that you can desire romantically and/or emotionally but not necessarily sexually (or indeed vice versa). Congratulations. It's a huge step.
Whilst there are few frameworks out there which will help you, a new one has recently come out which might be useful in this instance, even if it has one major drawback (which I'll cover after you've seen it).
On the right hand side you will find the familiar Kinsey Scale of sexual orientation. On the left, it has been extended further into a matrix with 'attraction types'. It's a far more flexible and intersectional framework to work with, however the drawback as I see it is that it still pigeonholes you into one box. At the very least you can change boxes over a lifetime. (I thought a long time ago, that I was an E0, but I have substantially shifted to a B2. These things you only find out after experimentation and self-work).
I would like also to point out that you do not have to "be" polyamorous, you can just "do" polyamory and believe it the possibility of ethical non-monogamy. Unfortunately, even in polyamorous circles many might not understand that you can be romantically asexual with one partner, and romantically sexual with another without comparing the validity of each one. Even trickier is for some to understand and accept that any long term relationship is perfectly valid and can be committed, whether or not it involves passion in the bedroom.
One way to explain it might be to use the language available to us from the monogamous world, and term them emotional affairs. It is perfectly possible to have a deep emotional (and - as it happens - romantic) commitment to one person without it being sexual - and many monogamous people recognise this. As the majority of us are aware of mono-normative thinking, this should resonate.
Transitioning Your Relationship
The other issue thrown up by your mail is that you have been sexual in the past with them - so my guess is that you and they are having difficulty transitioning without it being perceived as a form of betrayal. This for me is a bigger issue, since your identity is primarily your own problem, whereas transitioning a relationship is difficult for others too.
We all have built in expectations around our relationships and a big one concerns longevity of the relationship form. That you meet, fall in love and become sexual with one person and break up if you are no longer sexually attracted to a person is considered the norm. And yet, even in the monogamous world people break up and get back together again - I have a feeling that more might do so, if their break ups hadn't been so hurtful.
By transitioning without rancour you might be giving your relationship the best chance to rekindle sexually at a later stage. The pressure of 'having' to be sexual with someone, is more likely to kill desire than anything else. And after all, it may be that you are simply going through NRE (new relationship energy) and totally intoxicated by a new person; perhaps once this has a chance to settle, you will find your sexual energy can be balanced between your partners.
There have been references lately in the media to 'maintenance sex' - the kind of duty sex needed to maintain a relationship. The kind you don't necessarily want in the beginning, but you get into after a while. Depending on the type of person you are and how your boundaries are affected by this action, you may also be able to apply this to your relationships. Personally, I can't do it, but I recognise that it works for some.
If you are like me, unable to do maintenance sex without stepping on your own boundaries, then I advise transition of your relationship. Take the time to grieve without rancour and honour all your feelings. Leave the future as it is - unknown - and above all open to all possibilities. If you and your partners can find a way to keep the parts of the relationship that work for you, then you will be more likely to embrace change. And next time you start a relationship, maybe consider leaving expectations about the future aside.
Read next: "Downgrading" Your Relationship