My Thoughts
After watching yesterday's episode, this is what i felt about Dev's feelings:
Dev was extremely restless since 2 days. As he was the one who've hurt Sona badly. And after fighting with Dev over breaking the mobile incidence, Sona didn't meet Dev for the whole next day. If you guys have noticed, the day after the mobile incidence, Dev couldn't meet or see Sona for once. And the next day she didn't even accepted the phone from his mom and was angry on him. And she made it clear, when she said main aapko hi mana kar rahi hun Mr. Dixit.
He was restless as she was angry on him and was not talking to him properly. That restlessness leadt him to personally handing over the mobile with a very sweet apology. And he told her that he can't take it that she's hurt because of him.
According to my thoughts... He want Sona around him everyday. Whether they are fighting for something or their cute nok jhok's, their interfering in eachothers life. All's ok with dev. But he can;t take it that Sona is hurt coz of him or She's angry on him and don't want to talk to him. And that's the reason he made so much efforts for her.
Now Something about Tina:
I also loved Yesterday's Dev and Tina scene. Tina is really a cupid. She always remind Dev that he's similar to Sona. Like the ways she told him that he's Ziddi the same way Sona is. And during jodi.com, she stared at him and he accepted: Ok galti meri hai.