Because in the movie (spoiler I guess??) Deadpool wasn't supposed to know his name while at the Farm, so he managed to snatched his ID card or something which had his true name on it, which was Francis and he teases him about it relentlessly. Like a coping mechanism almost id say.
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Its a disrespect thing and a general pet peeve.
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Its a disrespect thing and a general pet peeve.
-Deadpool