However, you don't have to identify as asexual to dislike sex.
Nowadays we are born into a porn-fed generation in which reality doesn't meet expectation, and this can cause disinterest in the real thing. It's not uncommon to enjoy pornography more than sex, or to prefer the self pleasure that may come with it to touching another human. Self pleasure is quick, easy, self-indulgent and to the point, while sex isn't necessarily so. Researchers have even suggested that over-reliance on porn can actually re-wire the brain so you favour it as your outlet for sexual gratification.
There is also admin in sex which turns people off it. From hygiene and grooming to foreplay, mess, and clean-up, sex isn't a straightforward "in and out" experience most of the time. Some people find all of this too much – especially when they've got other things going on in their lives, like stress at work, children, mental illness, etc. Like anything else, the concept of sex can elicit feelings to the tune of, "I just can't be bothered".
Lacking intimacy
A lack of intimacy with your partner is a more obvious reason for disliking sex. This could be because you've been together a long time and sex feels routine; it's "always the same", as it were. Or, you may feel you've lost a connection with them – sexual chemistry is not static, after all.
Because sex can become so predictable, some people start to dislike it because they don't like the way it has to unfold. By this I mean, who initiates sex and how, then how it plays out. It can be very hard to mix this up when one way is what you've always known.
Your mental health is big factor in not liking sex. I've written about this before, I know stress and anxiety, for me, result in being completely disinterested in sex.
Those who suffer from depression or other mental strains may understand this too. When there's a dark cloud hanging over you all the time, the last thing you may want to do is be sexually intimate. There's too much negativity swirling around your head.
Physical problems (including erectile disfunction, premature ejaculation, delayed ejaculation, inability to orgasm, pain during penetration, and so on) can cause anxiety and warrant feelings of inadequacy. This can easily result in a dislike of sex altogether over time, as you shut down emotionally to the concept of it for physical reasons.
Avoiding sexual contact
Sexual Aversion Disorder, or SAD, is an assiduous and fear-based avoidance of sexual contact. It is a clinically-defined mental health disorder and is often rooted in trauma. People with SAD experience panic, distress, and residual pain during sex and their bodies and minds have formed a severe aversion to having it at all.
We can't forget age as another major factor. As we get older, we can become less and less interested in the experience of sexual pleasure. This can be because of mobility, biological cycles (e.g. menopause), or other physical and mental issues that come with ageing. Studies find that sex is simply less likely and less satisfying as you age, too.
If you don't like sex for one or more of these reasons (and would like to do something about it), the internet is your best friend. Practical solutions can be found online, both from professionals and other regular people just like you. If you think something more serious is causing your dislike of sex (especially if it's SAD), psychosexual therapy with a qualified psychologist can be helpful. It can lead you to an understanding of what in your subconscious prevents you from having a joyful sex life, and can provide evidence-based solutions to work through the issues.
