proximity friendship
A friendship that is formed when two people are put in a situation outside of their control. Most applicable when the two individuals have little in common and otherwise would not form a relationship.
Jim: "So how did you and Bob meet? The two of you don't seem like you have much in common."
Frank: "I was on a skiing trip and Bob and I ended up on the same gondola...I guess you could call it a proximity friendship."
Frank: "I was on a skiing trip and Bob and I ended up on the same gondola...I guess you could call it a proximity friendship."