From Rohan Healey's Greeks to Geeks: Practical Stoicism for the 21st Century:
"Stoicism and Relationships: In Sickness And In Health
Relationships make up a huge part of our life on Earth, sure there are the obvious ones like familial relationships, romantic relationships, work, friends, neighbors etc. But as well as those the fact is that every time you engage in a conversation with someone on the street, a police officer, or a shopkeeper that too is a relationship. Any time you are relating with another is a relationship . . .
There are two main Stoic points that should be remembered in any relationship, the first is that you do not, and cannot even if you wanted to, control the thoughts or actions of another person, people will do what people will do, you can offer advice, or tell them what you'd prefer, but in the end they are their own being . . . The second point is to have full respect and unconditional love of your friends and family, while reserving opinions and judgment for their actions only . . .
Remember that a relationship is made up of a series of deals, or agreements, 'I will do this, as long as you do that', when someone breaks one of these agreements the two (or more), the people involved, must look at the damage and decide whether to continue together, or what new agreements need to be put in place to continue the relationship. Try not to get caught up in believing that these agreements are more than what they are, to begin believing that they are sacred pacts or promises (never make a promise that is determined by forces outside of your control), or that there is good and evil involved, there is not . . ."