Possible Clues:

• 'It's you! What a surprise!'
• Greeting to an unexpected visitor
• "Hello, I didn't see you there"
• 'I'm surprised to see you!'
• 'Didn't see you there'
• 'Didn't expect to run into you here!'
• "Funny running into you here!"
• 'I wasn't expecting you'
• 'Huh, didn't expect to run into you here!'
• 'Wow, it's you!'