They're 'grown-up' [='mature'] enough to deal with the situation.
Their children are all 'grown-up' now. [=are adults now]
Her books appeal to both children and 'grown-ups'.
(..) No, I'm embarrassed. Oh, come on, we're all grown-ups. We've all done it. Me! Me-me, too! I'm a grown-up and I've done it! Fine. We were out one night, and things got a little spontaneous. Oh, that sounds juicy. (..)2016 TvShow: The Big Bang Theory Title: The Positive Negative Reaction Season: 9 Episode 16