It really should come as no surprise - since a male's sexual desire is so driven by their cock, and it even comes into play with feminization. First thing to get out of the way - the majority of dressers and those who desire feminization play are straight. This number blurs more with those who fully want to transition, but for those who want to be dressed by a woman and have a relation with her too, those I find to be straight lesbians. Meaning in male-mode they are sexually attracted to women, and that does not change when dressed.
With that out of the way, there is still a large spectrum in this main group, but regardless of where that break down, there is a lust for a strap-on. Images, like this one of Mistress Adrienne in a vintage North Beach Leather jacket and what is probably a 12" black dildo is powerful and erotic.
For many dressers, myself included, dressing is a form of submission. In fact, we desire the woman to actively encourage or enforce our feminization, even on a temporary basis. So in someways, the cock becomes part of the feminization on a sexual plane and we are penetrated orally of anally. It really is more of a form of sexual dominance by the female to further make the dresser identify and emulate the feminine. This is also why there can be a strong desire to have this done from a woman, but repulsion from a biological male or even another dresser.
Here a kneeling and feminized slave begins to suck on Mistress Victoria Valente's strap-on. She is powerfully dressed in a leather officer's uniform including riding jodhpurs and cap. Her legs are spread slightly and hip and cock thrust forward. Her black leather gloved hand sits on top of her hooded slaves head, ready to guide and control the interaction. This is more of power and reinforcing her dominance. It is erotically charged as she transforms him into her sexual toy. For the male it can be mildly humiliating, but for the dresser, it is more akin to accepting a feminine sexual side. As the experience grows, soon she can relish in making him gag on her cock. There is also the chance for so much teasing and taunting... not that the slave can object, especially with their mouth full.
"Crawl over here, slut, this cock is not going to suck itself"
Yet another enticing and powerful image. One can imagine crawling with their hand behind their back and being commanded to slowly kiss, lick, and eventually suck her strap-on. Her booted legs are positioned well to wrap around their back to thrust deeper into their mouth will her black leather gloved hand control their head.
For women, the sky is also the limit. Mistress Damazonia stands clad head to toe in leather with large strap-on, as does the other woman to her right with a very long phallus. Within reason, as the training progresses and larger and larger strap-ons can be used, futher allowing disparaging remarks about the feminized slaves own penis.
Their is guidance in this as well. Both Mistress Maria and Fetish Liza appear to look on, monitor and instruct their feminized sissy on their technique and application. The act is again, one of power, domination, as well as reinforcing their authority.
Sucking is just the opening. Sucking leads to fucking. Perhaps there is no stronger female statement of sexual power over a feminized male than pegging them. Make no mistake, once a male has been pegged by a female, she always has a strong claim of authority over them.
Lets not forget about the feminized slave's own cock. It seems that feminization goes hand in hand with chastity and one of the first action many Mistress' take is to put their feminized play thing into chastity. This definitely focuses the slave, as well as well combined with the above further reinforces them as feminized and submissive. But, as shown, the feminized slave can futher be made just a toy for the Mistress.
This particulare dynamic is expressed well with a strap-on being applied above his locked cock, so the Mistress can either ride him to her hearts content, or have him do the work and use the strap-on where it is about him pleasing her and the locked cock emphasizes that his orgasm is secondary.
But there also is the Menage A Trois - which is the dressing realm is Mistress and her friend double-teaming and overwhelming the feminized slave, stuffing them from both ends
Feel free to drop a line to me and we can see where it goes