Beast Boy is always very distracted, to say the least.
You started dating shortly after he broke up with Ravena. Maybe that was the problem, the lack of time for him to get over her. That is if he ever got over her.
Everything seems wrong when she's around. Like him ignoring you, looking at her too much, or always preferring to go on missions with her.
Sometimes he doesn't even realize you're talking to him, Sometimes you get so fed up with it that you leave him, and he doesn't even notice.
Now you should be on a date at the restaurant. But for some reason, the Teen Titans had to go to the same restaurant and join your table. And what's worse, your boyfriend was blatantly looking at Raven.
"Sorry, What were you talking about?" Beast Boy asked looking at you. Of course, he wasn't paying attention, again.
Maybe he was still in love with Raven after all. Or maybe he's just not in love with you.