Related Clues:

• Very funny (1)
• [That cracks me up]
• Apt cryptogram of "aha"
• [Your comment amuses me]
• Texting titter
• "Take that!"
• Texter's 'that's funny'
• Pun reaction, perhaps
• IM guffaw
• Titter sound
• Modern lead-in to cat
• Text giggle
• 'OMG ur a riot!'
• Alternative to :-)
• Online ha-ha