I'm pretty sure its Jason. Alison's older brother. In the books Aria had a crush on him when they were younger. So I think its Jason but I'm not sure. But hopefully it doesnt ruin Aria and Ezra's relationship! I love them together!
Alison's brother Jason DiLaurentis will be the guy who comes between Ezra and Aria. He has known Aria longer then Ezra has known Aria, his own girlfriend. He is the exact opposite of Ezra and it will be nice to see how he acts with Aria and what Ezra wil do.