Unfortunately, a frequent byproduct of aging is a reduction in sexual availability, drive, desire, prospects, cooperation, etc. Take your pick. In a partnership, it may be you, or your partner. Or both.
I'm not young. My wife is older than me. She has little interest, and what rare sex we have is for my benefit. There comes a point of discomfort and other interests. I've found a reduction in my ability to perform, produce, and to maintain. But it doesn't mean my interest is gone.
Over time, especially as I've grown older, the prospect of sex has diminished, and I've found myself drawn to elements of sexuality that support where I am. If I can't have sex much, chastity seems a good fit. If I can't have sex much, fantasy is what remains, and though neither my wife nor I would stray from our bonds, the thoughts entice. My wife has no interest in female domination, though we've played around the edges a bit. It becomes fantasy.
There is no possibility that my wife will have an affair, nor would she entertain the idea of a sexual encounter or relationship with another man. It's an easy fantasy, safe, as it will never see the light of day. My wife will never have me clean her up after a tryst, as she won't have one, but she's happy to have me do it in the rare occasions we have sex, and those infrequent moments of subservience remain cherished fuel for fantasy.
I wish that I'd discovered the element of sexuality that encompasses FLR, femdom, and who knows, maybe cuckolding too, when I was younger. Would I have accepted it? I don't know. Presently, if I'm not having sex, it's a substitute to pretend that I'm not allowed to have sex, that I'm kept in chastity, and occasionally, she will insist on it, though it doesn't hold her interest much. I "discovered" the elements of sex that touched on female domination, FLR, and hotwifing, cuckolding, etc, not that many years ago, while researching a writing project. It struck a chord, and the more I looked into it, and the more I read, it resonated. At first exciting, even forbidden, it's become the core of my fantasy world, my turn-ons, and the imaginary life I'd lead. But, that's all it is.
I am on the road most of the time, mostly out of the country. At the moment, I'm tied into some events near the Black Sea. My wife is home alone, and I don't mind fantasizing that she's cheating. I like to imagine that her sex drive is strong, that I'm not there to fill her needs, and being a loving and supporting husband, I'm understanding when she strays. I like to imagine that she doesn't care if I'm understanding, that she's strong and independent and while she loves me, she's not going to go without. My fantasy is self-serving; it's a narrative I create to solve my own problems, not hers. She isn't getting sex at home. She isn't interested. I'm not getting sex in the field. When I do get home, it's brief, and sex is rare. My self-serving narrative grants her a libido, and I can pretend that she'd be interested in me, too...even if it were to make a point of cheating, or or insist on chastity, or to punish...the fantasy is that she'd be interested at all, when I know she really isn't. The fantasy is selfish: it's not about her; she doesn't care. It's about me, that she'd actually have an interest enough to care if I were denied, or cuckolded, or bound by a promise or contract. It's about me, really. In my fantasy I matter, I'm important to her. She cares. It's only a fantasy, but at this stage, it's all I've got.
I'll take it.