Past Lives
It hurts to watch, a lot. You just know that they are meant for each other, or were meant? will? Despite what she says, how they look one to another, how they easily and comfortably talk and laugh, how much they enjoy their company, but their circumstances won't allow it.
I just feel bad for the husband, poor lad has to stand there watching all of that and at the end comfort his wife who just said goodbye to the love of his (past) life.
On a more technical side, masterfully directed and shooted, the frames perfectly encapsulate how our protagonists wander in this sea of doubts and emotions, and also we get to really see all of that in their movements, eyes, body language and how they too realize that about the other and end up not doing much about it.