But “literally” doesn’t mean “truthfully”. It’s not the opposite of “false” it’s the opposite of “figuratively.” You’d have to use it in a case where what you were saying could be mistaken for metaphor rather than a case where what you are saying could be mistaken as a tall tale. I think of watching Bob Saget react to Norm MacDonald telling one-liners at a comedy roast. While the audience was almost silent, the comedians on stage were laughing their asses off[1]. Saget laughed so hard that he fell off the couch onto the floor[2].
[1] You knew this was a metaphor, no ones ass fell off.
[2] Your biggest hint that I meant this actually happened: I just used a metaphor to describe everyone as a group so singling Saget out in a follow up sentence suggests I am differentiating his reaction and “fall on the floor laughing” doesn’t differentiate from “laugh your ass off” as metaphors
Like my example above, if I wanted to express that I laughed so hard that I momentarily lost control of my bladder, which would be more effective:
a) “I pissed myself laughing”
b) “I really pissed myself laughing”
c) “I actually pissed myself laughing”
d) “I literally pissed myself laughing”
e) “I pissed myself laughing, no joke”
f) “I - and I’m not fabricating this, this really happened - pissed myself laughing”
g) “I know that when people say this they usually mean it metaphorically, but I don’t: I pissed myself laughing. I had to take a very shameful cab ride home and change.”
Who knows? Any of those could be a joke, any of the them could be true. I’d suspect the teller had actually peed in their pants if the overall story was positioned as a story about an embarrassing thing that happened to them and I would suspect they were exaggerating or joking if the overall story was positioned as a story about a funny joke. For most people, peeing in their pants is a more important experience than hearing a funny joke, so it’s unlikely to be used as a mere adjective to describe a joke if it actually happened.
I’d have to judge by tone and context. It doesn’t matter how much you protest that you are being truthful, you simply can’t talk about laughing hard enough to lose control of your bladder and be 100% assumed to be serious even though that is a real experience people have been known to have. There’s no magic word that is going to solve that problem.
The only way “literally” could do what people in the anti-figurative-“literally” crowd seem to want it to do is if it was a different part of speech. It would have to be a safe word or an escape character for conversations. The only word I can think of that has a similar place grammatically is “sic”, which always appears in parentheses or brackets because it cannot be used as part of a sentence.
Honestly, saying “literally” can’t be used figuratively strikes me as the same as saying you can’t write “blue” in black ink.