What is the deal with having to say goodbye repeatedly until a person drives away. I've noticed this more and more. For example, you've had a couple round and it's time for them to leave and they say " right well, we better off" 
As you open the door for them to go you will say "right I'll see you later"
They reply " see you "
But normally your other half has followed that up with a "goodbye"  so they say"see you later" to her too. 
Then it's madness as they duck their heads into their car you have to squeeze a "bye" in. 
And then you wave which is the mime for goodbye. 
Should I text as they drive up the road?,  send them an E mail.?

In future it's one goodbye and then I shut the door behind them. 
Why do we not repeatedly say Hello to someone? 
"hiya, hello, welcome.."