He does this HYSTERICAL impersonation
of Stephen Hawking having phone sex.
The Big Bang Theory Season 2, Episode 11
Yeah, it's HYSTERICAL.
The Big Bang Theory Season 4, Episode 22
Hysterical.
The Big Bang Theory Season 4, Episode 20
I think I'm HYSTERICAL.
The Big Bang Theory Season 7, Episode 12
That's HYSTERICAL.
The Big Bang Theory Season 7, Episode 15