What is swinging or partner swapping?

Swinging can mean many different things:

     looking at each other
     having sex in front of others
     have sex with others
     having sex with someone other than your partner (with or without his or her presence)
     behave very provocatively in the presence of others
     touching each other intimately in view of others

This means that swinging is not the same as cheating!
When swinging, everyone knows 'how, what and why' and everyone involved does everything voluntarily and effortlessly.
Everyone who participates has been informed and gives permission.