I am sure you have heard of designated drivers, but have you ever considered the possibility of designated martial artists? No, I am not joking.
And I am not necessarily talking about someone getting falling-down drunk.
Almost Impromptu Bodyguard On occasion, one of the two of us has had a need for a mild painkiller for an injury -- not often, but it has happened.
While not completely incapacitating the person, the medicine does dull the senses.
Also, on occasion, one of us will imbibe a little alcohol, maybe at a reception.
Not rip-roaring drunk, but again ...
dulled senses.
The same with some rough bouts at the dentist.
You probably wont believe this, but ...
when one of us is "mentally dulled," the other automatically goes into alert mode.
It's not a big deal or a major conversation.
One of us simply says, "I'd like to have a glass or two of wine at the birthday dinner, this evening.
" The other responds, "That's fine.
I'll drive, and ...
" "Yep.
" And that's it.

Note: No, we don't disagree about who will and who won't.
We are pretty in tune with each other, and good communicators.
So, it works out.

The Bodyguard Leads There is an added benefit: If there were a confrontation, then the more "sober" person would probably take the lead position in any confrontation or altercation.

Note: Although a good tactic would be to have the slightly inebriated person feign being a lot more "sauced up," and while acting the part, get close enough to ...
ah ...
I should write action scenes for movies.
Maybe not.

This is just one more piece of the puzzle.
You have always known to take care of a child or loved one.
Now, you are just extending your care to include someone who, for some reason, can't react as well as normal.
And you have just raised your level of martial arts mastery, when you decide to communicate with your martial-arts peer ahead of time about all of this.
Not that anyone else need to know that you are acting the part of bodyguard.
You have heightened senses.
That's about it.
As I said, nobody will notice.