I've had other posts on this subject and i do think i am getting closer to solving the riddle on hocd, gender confusion, trans attraction and so many other problematic sexual behaviors. I consider "straight" porn and jerking off to be the main culprits, with jerking off sealing the deal on problematic behaviors and addictions. That is, aside from "straight" porn not being a heterosexual act (but rather bisexual), aside from the fact that watching others have sex is abnormal and unhealthy, what really makes this pathological is the actual rubbing of the penis by oneself. In an act of natural sex, a man will receive various sensory inputs, the primary ones being sight, hearing and touch. There's also smell and taste that play a role and the PMO experience removes but i do not think those are as important as the sight, hearing and touch. In a normal, natural sex act, the sensory input will be 99% that of a woman (you touch her with her hands, you touch her with your penis etc). The main problem however when it comes to jerking off is touch. Touch is a major sensory pathway and the most archaic one. The initial organisms relied on touch as the primary sensory input and we as humans also use it intensely. It is what provides a sense of "proof" of the existence of an object (that's why kids touch anything that is in their close proximity and that's why anyone has a tendency to touch something to learn more about it). Sexual stimulation happens with a thought or a visual input, which are both imagery. The thoughts are a representation of a former visual input and new visual inputs are processed as representations anyway so at the end of the day you're simply dealing with visual representations. In a typical porn/erotic scenario you will also get audio input but that is not always the case. What happens next is crucial. You will usually get an erection. For your body and mind to confirm the visual and audio inputs it will need confirmation from the sensory inputs. A well adjusted individual will get aroused but in the absence of a sensory input (woman/vagina) will lose that erection. But with jerking off, something extremely perverse happens. You start touching yourself to confirm the previous stimuli but the inputs you are receiving are upside down. Your mind expects a woman/vagina and it receives the sensory inputs of a penis/man. And this juxtaposition does not only happen once, it happens hundreds or thousands of times. As you probably have heard, neurons that fire together wire together (which happens decisively because you also get enormous amounts of pleasure), so you get the very undesirable and unhealthy woman=penis=vagina=man. Depending on the individual's specific pmo history (did he start with women only or with "straight" porn? what's the ratio of solo women/straight porn he used? how much does he use each? Did he use porn before or after first real sex experience? what is the ratio of real sex/pmo he has? and many more factors) the former association will lead to various sexual problems or dysfunctions. As a side note, ejaculating on yourself/in your hand when jerking off is very damaging. You have to look at HOCD, transgender/shemale addiction, thoughts of being of the opposite gender as rooted in the same fundamental misrepresentation that comes from PMO (mainly M, jerking off): woman=penis=vagina=man. This also explains why so many (young) men have ED issues - when it comes to real sex, their mind is wired to feel a penis and not getting to feel it disorientates them. The mind is trained to get erect by feeling and rubbing a penis, which in a normal sex act does not happen. They in turn receive another sensory input (vagina) they are not used to and do not associate with "sex".