[K. in Cleveland]

Yes, I agree with Dan and Jennifer, if she cannot speak up for herself you should definitely be there with her. You know her best, and you would be able to tell if something is bothering her even if she's not saying so. Then you would be able to tactfully deal with it and intervene while maintaining the friendship... I always think of it as a friends with benefits kind of thing between couples, however I am aware that some couples are just into it for the sex... but I do feel that for new swingers a friendship with the other couple would probably be easier, and more comfortable.