We've recently passed another milestone. The teenagers are too old to play. If you asked them, that's what they'd tell you. It's actually not true. What they do isn't any different than when they still called it playing with friends. It's just not cool to call it that anymore. Instead, the acceptable term is hanging out. So instead of "Dad, can I play with Becca?" It's become "Dad, Molly and I are going to hang out". My reply hasn't required any adjustment. "Be home for dinner" still does the trick.
I don't recall exactly when that happened. But the milestone is still visible in the rear view mirror. It's good to see your kids are growing up. It's also nice to have one that isn't too old to play. I think she just may be smart enough to realize that she never will be.