Or making fun of me. Or seeing through me.It stung me when he finally came out with it. Only someone who hadcompletely figured me out would have said it. “If not later, when?”
His "If not later, when?" offends Elio because it hints at his looking for a better moment to speak (to speak or to die) and their continuous delaying of approaching the matter at hand by speaking, maybe because speaking will change something between them, because speaking means something.
In this case, Oliver himself is picking at his own scab, as he always says "Later!" Him saying this to Elio is ironic because the two of them are both delaying admitting their true feeling and Oliver is telling Elio to hurry up and confront him, even when all signs say he doesn't want to.