The Private Benjamin star began dating Russell in 1983 after they co-starred in Swing Shift, and they have become one of the few Hollywood couples whose romance has stood the test of time.
They welcomed son Wyatt in 1986 and Hawn reveals their second film project together, 1987's Overboard, was extra-special.
Speaking on Britain's The One Show, she says, ""It was fun doing that together, but that was our second movie...
""This was after Wyatt was born and Wyatt was nine months old and took his first steps on that movie. It was pretty fun.""