Pretending (n.) is beyond many creatures that express fear, joy or pain.
Pretending (n.) poses no threat to the concept of pain; it makes it more complicated, like the use of money.
Pretending (n.) and its opposite exist only where there is a complicated play of expressions, as false moves exist only in a game.
Pretending (n.) cannot be ruled out by looking into someone, for his secret thoughts, if in Chinese, would still leave the question of truthfulness.
Pretending (n.) would be impossible if one could never know what another feels, since it means getting someone to guess wrongly.
Pretending (n.) pain is not expressed by I am feigning pain on a level with I am in pain, which is no utterance of feigning.
Pretending (n.) lies in the intention, since pain behaviour could be imitated exactly without pretending.