that would be hysterically, Sean
Uhh, before you try correcting grammar as a way to make yourself look superior and divert attention away from the flaw in your argument, maybe you should make sure the way you suggest is the only right one. Our esteemed colleague, Sean Smith, was using hysterical as an
adjective, not an adverb. Would you say that a man looks "oldly?" No, because you're not describing the way in which the man looks, but what he looks like. Similarly, Sean was not describing the way in which you act, but what you act like.
Stop acting "superiorly" when you're not.