Used to express that something is unbearable or hard to stand.
Long explanation:
The ~に堪えない grammar point is used when the speaker wants to express that a situation is unbearable, intolerable or hard to stand/sustain. It translates to 'can't stand' or 'unbearable' in English. The formation of this grammar concept differs depending on whether nouns, verbs or い-adjectives are being used.