Does my friend need to show my return ticket home when taking domestic flights with ESTA?

My friend is visiting/traveling US with ESTA, and my friend had to show the return flight ticket when first departing from hometown to US (to ensure that they are not just staying here in US).

Now, my friend is taking a domestic flight from CA to NY using Virgin Airlines, and I was wondering if showing the return ticket going to hometown is necessary in order to get on board.