Mammon was sick. Fever and all the things with it.
His temperature wasn't even THAT high, but of course, he was making a huge deal out of something that in the end wasn't even that bad. It's not like the end of the world would be coming if he had a little fever, and was just slightly hotter than he already was usually..
Either way, you had to put up with his drama. Lucifer assigned you to take care of him while he was sick, and so, no matter how dramatic he was, you still had to be by his side, reassuring that no fever monsters would come out to eat his money at night.
-- "A— ACHOO!"
A mountain of paper towels was huddled up on the side of his bedside table, with most of said papers falling into the trashcan underneath it, which was already almost filled. He wasn't looking good.. Not at all.
-- "Huuumieee'!"
He called out to you, his tone having a hint of a whine as he frowned, almost like it was your fault for his fever. You always told him to cover up more, and look now..
-- "Ya' ain't gonna do anythin' to help the great Mammon with his sickness..?"
He tugged on your arm, his actions being much closer to the ones of a clingy dog rather than the ones of a demon.