There is not the weighty expectation of monogamy which is often associated with romantic relationships people have a much harder time ending friendships so this was a bit confusing when I first read it. In terms of a friendship there is absolutely nothing stopping you from avoiding a friendship breakup indefinitely putting off the confrontation and just hanging out with other people rather than cheating on your friends. We assume that our friends will be around forever we expect that we'll be retiring together beat each other's weddings meet the family meet each other's kids but if there is a breakup we aren't just grieving the present loss of that friend but also the loss ofthat friend in our imagined future.