Like a Hand Talker, this is a person that insists on using there mouth to either spell or speak as they text on their phone. Some speak out loud while some simply mouth the words or letters in an overly exaggerated fashion (usually caused by their slow texting skills).
My wife is such a Mouth Texter, she just got her new iPhone and spends all day Mouth Texting as she sends all her sisters texts about her new apps.

OMG, this guy in Math class next to me is a Mouth Texter and I swear I heard him text that he was going to ask you to Prom!
by KIA_Ostee October 21, 2011
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