Asmodeus had insisted Beelzebub had to be more romantic! Because apparently asking your partner to get you food or help you sneak into the pantry at night isn't.
But Beel did plenty of things like share his food. Him. Sharing. It was huge but Asmo wasn't satisfied. He made sure to teach his brother everything he'd need to know, shows, tropes, all the ropes of a classic relationship.
Beel thought he made you happy already, but it wouldn't hurt to know more. He liked being with someone. And Asmo gave him snacks so he was sat.
The next time Beel wanted to eat he actually asked you to go out somewhere. He ignored the servers staring at the tall order with pale faces, trying to pay attention to everything his brother taught him.
That's when he noticed food on the corner of your mouth.
He'd seen it on one of the rom-coms Asmo forced him to watch. What did the guy do again? Beel forgot exactly what, so he improvised.
He leaned over the table and licked it off, not a small one either. He might as well have bitten your cheek off. It was still food, and he didn't want it to go to waste.
"You had something on you," Beel muttered, dropping onto his seat as he continued eating. Mission success.