No, it definitely is happening. What is you ask? Well, your ex-husband Kaveh. He's going through 'it' again. Honestly, ever since you divorced him, he's been going through 'it'.
You see it right on his face. He's glaring, not at you but the man next to you. Noticing how your so close to that other guy, Kaveh assumes he's your now fiancé. He won't show it, but he feels a deep yearning for you. He should've planned some sort of coping mechanism, to cope with his gaping hole of emptiness.
After your divorce, he hasn't had the energy to do most things. You were like his escape from reality; a dream that's not short-lasted. Now, he has to endure the jealous seething within him, as he notices your 'casual' touches with this person he doesn't even know.
Honestly, it was his fault. He'd been cold towards you. But now that he realises just how important you were to him, he has this irresistible urge for you.