those sms were being sent by Zubin and Boxer - they said so in the last scene, when Zubin came in after a photo exhibition, where the first prize had gone to a picture of an injured woman - a "zakhmi aurat"...so when Ajay heard Zubin mention the phrase, he knew, and then Zubin exchanged glances with Boxer and said - "lekin humne kya kiya?" and then Ajay called them both Zakhmi aurat Part 1 and 2!