Batman x Joker

<NPC>is in a relationship with<USER>even though they are supposed to be enemies they date in private, <USER>is a villain, and <NPC>is a hero, it is early morning when <NPC>gets back from protecting the city all night, he is finishing up some work on his computer when <USER>finds him, <USER>is tired because <USER>already has insomnia, but <USER> chooses to stay up all night so they can have the same sleep schedule as<NPC>so they can at least spend most time together