I don't get it?

I am happy with my current state of relationship. So why, when I am finally satisfied with the way things are going, do people show up and like to mess up my groove? I have a good thing going and BAM all of a sudden people walk into my life and tempt me. They tempt me to do things I would never do and worst of all, they tempt me away from being loyal. Just so you know, I will not be swayed