The Great Believers by Rebecca Makkai:
As the group tunred toward the door, Yale saw another guy—no one he recognized, at least not from this distance—whisper something into Charlie’s ear, then turn back and look straight at Yale. But Charlie never turned.
Yale’s feet stuck to the ground quite a while. The emotions he’d have felt if this had happened yesterday were mitigated by the fact that he wasn’t infected. It hit him now that he’d outlive Charlie, that he’d be the one looking back on this in fifty years, telling Charlie’s story to someone just as Nora had told Ranko’s to him. With less longing, granted. He couldn’t imagine he’d see this as the great lost romance of his life. He wanted to be invisible so he could follow Charlie into the bar, see if he was drowning himself in beer. Instead he walked home, straight into the wind, and by the time he got there his skin was numb.