
"Made up my mind to date both of them
by pretending to be TWIN brothers."
The Big Bang Theory Season 9, Episode 14

but when they're TWIN primes,
The Big Bang Theory Season 9, Episode 12

...since I beat out my TWIN sister
for the "Did It On The Potty" trophy.
The Big Bang Theory Season 8, Episode 23

Now, I've lived my whole life dealing
with the fact that my TWIN brother is...
The Big Bang Theory Season 1, Episode 15

I have a TWIN sister
whose assaults began in utero.
The Big Bang Theory Season 3, Episode 17