Possible Clues:

• Texter's "Zounds!"
• Small-screen gasp
• Texter's ''Wow!''
• Texter's "Horrors!"
• "Srsly?!"
• 'Can u believe it!'
• 'I'm shocked!,' in a text
• Texter's "Unbelievable!"
• Texter's ''Holy cow!''
• "r u kidding?!"