Say Jack used to go out with Sarah (quite a few years ago) and they had a bad breakup, which Jack admits is fully his fault.
They haven't seen eachother in a while. In the intervening time, Jack's become friends with Jamie. Jack takes some time off work, and Sarah fills in for him. She and Jaime become very good friends. Jack comes back, and then he and Jaime start going out. Jaime is aware of the nature of Jack and Sarah's break-up.
Would you say this counts as 'bad' under the whole "don't date your friends' exes" thing? Is Sarah justified in being upset?
I can kind of see Sarah's point... And kind of not. The break up between Jack and Sarah was really bad, but it was also a few years ago. Jack and Jaime mantain they had no intrest in eachother before he took time off work. I think Sarah would find it easier if they had, but Jaime say's definitily not.