
That would be
the MATURE thing to do.
The Big Bang Theory Season 11, Episode 15

I mean, we spent the whole
night trying to be MATURE,
The Big Bang Theory Season 7, Episode 14

how emotionally MATURE you are,
didn't you?
The Big Bang Theory Season 11, Episode 15

and that stands for
"MATURE audiences," buster.
The Big Bang Theory Season 9, Episode 21

That's very MATURE of you.
The Big Bang Theory Season 9, Episode 13