John continues to have a certain realism about his relationship with Lila; he doesn’t mistake it for a grand, youthful passion. The Bible’s Song of Songs is known for its romantic, even sexual overtones, and these took on a fresh meaning for John after he met Lila. He doesn’t assume she feels the same passion and is okay with that. Remarkably, he implies here that if Lila were to fall in love with Jack after John dies, he could accept even that.