The old "tea analogy" covers it perfectly - see the bottom bit for consent when unconscious
You say: “Hey, would you like a cup of tea?”
If they say, “Yes, I would love a cup of tea! Thank you!” then you know they want a cup of tea.
If you say “Hey, would you like a cup of tea?” and they hem and haw and say, “I’m not really sure,” then you can make them a cup of tea or not, but be aware that they might not drink it.
If they don’t drink it—and this is the important bit—then don’t make them drink it.
You can’t blame them for the fact that you went to the effort of making tea, on the off-chance they wanted it. You just have to deal with them not drinking it; you making tea doesn’t mean that you are entitled to watch them drink it.
And if they say, “No thank you,” then don’t make them tea. At all. Don’t make them tea; don’t make them drink tea; don’t get annoyed at them for not wanting tea. They just don’t want tea, ok?
They might say, “Yes please, that’s kind of you.” And then when the tea arrives, they might not want the tea at all. Sure, that’s annoying, as you’ve already made the tea, but they remain under no obligation to drink the tea. They did want tea, now they don’t. Sometimes people change their mind in the time it takes to boil that kettle, brew the tea and add the milk. And it’s ok for people to change their mind. You are still not entitled to watch them drink it.
If they are unconscious, don’t make them tea. Unconscious people don’t want tea and can’t answer the question, “Do you want tea?” because they are unconscious.
They may have been conscious when you asked them if they wanted tea, and they said yes. But in the time it took you to boil that kettle, brew the tea and add the milk, they are now unconscious. You should just put the tea down, make sure the unconscious person is safe, and—this is the important bit—don’t make them drink the tea. They said yes then, sure, but unconscious people don’t want tea.
If someone said yes to tea, started drinking it, and then passed out before finishing it, don’t keep pouring it down their throat. Take the tea away and make sure they are safe.
Because unconscious people don’t want tea. Trust me on this.
If someone said “yes” to tea around your house last Saturday, that doesn’t mean that they want you to make them tea all the time. They don’t want you to come around unexpectedly to their place and make them tea and force them to drink it, while you say “But you wanted tea last week!” They don’t want to wake up to find you pouring tea down their throat, saying “But you wanted tea last night!”