monogamous mean anything?

For some reason monogamous relationships are flexible to their vintage label. I've been discussing their modern version of the term and it's arousing and scary at the same time. If you agree to have a faithful relationship with one person, than why is it okay to be with other people while you're in the "faithful" bond. My friends have gone so far to encourage their partners to have sexual interactions with other people, and no one thinks that people who have boyfriends or girlfriends are off limits...what is wrong with this generation. I'm not sure if this could be awesome or awful for me but I'll take it for now.