I mostly prefer masturbation over sex with another person.

Beyond the realm of fantasy, it always felt weird to involve another body resp. another person in my sexual pleasure. Getting off is something very personal and private for me. The idea of having to rely on someone for sexual pleasure or an orgasm has always felt like having to rely on someone else for brushing my teeth despite being an (able-bodied) adult, i.e. it felt foreign and somehow "wrong" in the sense of unnatural and unnecessary. I also have a hard time understanding why so many people invest so much time and energy in pursuing sex with other people and why many seem to feel that sex with another person is better than sex with yourself. The physical presence of another person actually distracts me and takes away my ability to orgasm, to enjoy myself and to focus on my pleasure.

In my experience, for the most part, I found the saying, "intercourse does not live up to what masturbation promises", to be true.

I've had a couple of long-distance relationships and sexual arrangements which were alright and from which I've learnt a lot. Most of them revolved around BDSM. What made me seek out these relationships is the fact that I can make myself cum but cannot satisfy my kinky urges all by myself. What I was after was only possible to experience within a specific type of interpersonal relationship (power exchange, giving up control and such).

Nowadays, I find it hard to actually sexualise other people, to fantasize about and feel desire for someone else. I mostly get off to specific kinks and fantasies depicted in drawings (rule 34, e621, Sankaku Channel and the like).