She Said What - "Communication: Comparing Relationships to Your Own"

We go through it time and time again. Your man or woman scrolls down her social media feed and notices her friend's status update to "In a Relationship" and automatically he or she grows instantly upset at you. Or how about during the holidays when all of your friends are getting engaged left and right, meanwhile you're still waiting for your partner to make things exclusive with you? Is there any reason why you cannot be happy with the way your relationship is at that moment?