If just telling her what you want isn't enough for you to feel like you're communicating effectively, try asking her if you could add to it by telling her how you want it, and then maybe expand to how you're desiring to feel about it.

E.g. not just "I would like oral" but instead, "I would like oral, and I'd love to hear that you're enjoying it, however you want to express it." <- This is a request that is direct and specific but doesn't feel robotic or unceremonious IMHO.

I have ASD and my wife doesn't, so we've established that it often makes the most sense when we just explicitly just ask one another, "what can I do for you tonight?" Which leads to very specific answers about what we're wanting to get out of it and how we can best achieve that together. "I've been thinking about you in this way" or "I'd like to know what it looks/feels/tastes/sounds like when you ..." Followed by describing whatever action would best fulfill the desire, followed by any specifics and how we're feeling about it now. "Now that we've talked about it I'm definitely excited to see that" and such.

Dunno if that's helpful but there might be ways to make it feel more special while still being explicit and direct! Just talk about the how and why and how you feel about it.