I think it's mostly used with the gerund. However, if we take "bear" (which is a near synonym) , maybe there's some kind of reasoning possible; you use the -ing form when it's something you have already experienced and so relates to past events: "I can't bear/stand seeing somebody cry">everytime you've seen someone cry, it has been unbearable to you. "I couldn't stand/bear to wake up and see you gone"> this relates to the future , and to something the speaker hasn't experienced yet.
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