
Don't be SILLY. Just tell him.
The Big Bang Theory Season 6, Episode 23

No, no, no. You are my boyfriend.
Nothing you do is SILLY to me.
The Big Bang Theory Season 3, Episode 17

Silly frog. So funny.
The Big Bang Theory Season 6, Episode 19

to the possibility
that the truth may sound SILLY
The Big Bang Theory Season 12, Episode 20

and I told her
she was being SILLY,
The Big Bang Theory Season 12, Episode 3