[quote=@aladdin_sane]
...shared history...
[/quote]

That actually sounds like something that would have happened between the two. It is only logical that because they both grew up in the same city and same upper class circles that they would bump into each other. I am all in for what you have suggested, but I will throw in the fact that Nathan would, too, forget his encounter with Pierre for added dramatic value. Maybe there are some more recent interactions, perhaps a sarcastic battle of subtle comebacks at some gala or fundraising event in Manhattan. 

Also I like this new image better, looks more Pierre Athene and more manipulative.