In the final moments of the film Bill Murray whispers something into Scarlett Johansson's ear. This moment was improvised, as was the whole scene - including the kiss. It has never been publicly revealed what, if anything, was whispered.

Just Like Honey
Listen to the girl
As she takes on half the world
Moving up and so alive
In her honey dripping beehive
Beehive
It's good, so good, it's so good
So good
Walking back to you
Is the hardest thing that I can do
That I can do for you
For you
I'll be your plastic toy
I'll be your plastic toy
For you
Just like honey ...
The Jesus and Mary Chain