Just commit, no matter the response. Adding /s is akin to explaining a joke after you tell it. If someone doesn’t understand or pick up on the sarcasm, it’s not your responsibility to spell it out for them. You add /s because you don’t want to be held accountable.
And how did we do that? With other indicators. /s is just a more specific evolution of ;). But winky face is used for more than just sarcasm, so confusion develops. Thus, we have /s
Bring back winky face.
Yes daddy ;)