Possible Clues:

• Texter's "until next time"
• Texted ''ta ta''
• Texter's valediction
• 'Gotta go,' in textspeak
• 'Toodle-oo,' in textspeak
• Texter's bye-bye
• 'lol, peace'
• IM signoff
• 'Bye for now,' in a text
• Texter’s “ta-ta!”