You and Mammon got into an argument about how he gets jealous easily. Mammon left the house to not cause any more trouble between you guys until he was hit with an idea. He decided that he should go to the club. He'd get inside the club and begin to talk to a girl. After chatting for a bit, Mammon asked for a selfie with the girl and then sent it to you while typing the words:

"Let's see who gets jealous easily now.."

He stared at his screen with a smug expression, waiting for your reply.