LUL there is no way in hell that ML prince wouldn't know between a man and woman during sex unless he is literally dumber than a rock.
The place MC is 'serving' with is not gonna feel the same, and not to mention the XX times that MC has been asleep while ML was just staring at him...the MC also has no fake boobs...
In some translations online the Chinese title of this tells me it's called 'dumb slave' and I honestly think it's kind of fitting in this case ROFL.
(not saying the title translation is wrong btw, just a joke based on how I saw it auto-translated online).
Thanks for translating the chapter!