Notes with warnings for all of this fic (no spoilers):

I will not hold back on depictions of violence or blood/gore. There shouldn't be anything that bad in this fic, but you have been warned.

I will also not hold back on fucking swearing c:

There is no mention of MC or the reader in this fic. It is more so an exploration of Satan and Lucifer's characters and their relationship.

The OC that appears in a few chapters is not going to be the focus of the fic. I get tired of looking for fics that dive deep into the characters only to find that it's a fic where someone wrote their character in to the plot and then they become the focus of the story. No. This is a story about Satan.

For anyone that wants it, this can be read as Satan/maleOC, but it is written with no romantic or sexual implications. There will also likely be a joke later about Lucifer and Diavolo having a sexual relationship. It is not important to the plot, so if this bothers you, it should not be a big turnoff. That being said, they are very much fucking in this story–hence the title.

I have not planned it thoroughly enough yet, but there is a chance that the topic of self-harm is written into the story through the OC. appropriate warnings will be evident in the notes of chapters where it is mentioned if this occurs.

I am a simp for Satan.

Satan woke up today feeling the wrath beneath his skin ready to burst into the world, but like every other morning, he took the time to read the paper, await his brother's entrance into the waking world, and allowed his wrath to be washed away by the story of his current novel. This one was about a family of cats raising a dog.

As Lucifer unsurprisingly was the next to join him in the dining hall, his mind wandered to begin scheming his next act of violence against the eldest demon brother. Hmm. He would have to wait and see if Belphie would be conscious today. However, his detail oriented mind called out a small detail detected during his hate-filled side-eye. Lucifer had fixed himself a cup of coffee. This was a most unusual omen, and a clear indicator that Lucifer would not find rest today or tomorrow. For all the good that the prideful demon spoke of his beloved tea collection, he never was one to deny the effectiveness of demon-powered caffeine.

Satan excused himself with no words to get the paper. Perhaps there was some diplomacy drama planned for today, and Lucifer was preparing himself for a few nightmares of days when he forced himself not to strangle Mammon with company in the Devildom. As he absentmindedly turned the knob on the front entrance to the House of Lamentation, he was met with a panicked Barbatos. This day would not be an ordinary day.

Barbatos scarcely showed any sense of panic, fear, or–honestly–emotion other than love for his master Lord Diavolo. Something that could bring about this reaction of him in the open campus would not be good news.

"Ah, morning, young Satan," he hated that honorific, "I must see Lucifer immediately. Would you show me to his location?" Sensing the urgency in the butler's voice, Satan silently nodded and held the door for the butler to step inside. In quick but calm strides, he showed Barbatos directly to the dining hall where Lucifer sat with his now empty cup of coffee. Surprisingly, Mammon had been the next to emerge from slumber as he sat playing on his phone at the table. He could hear sizzling from the kitchen, and assumed that Beel had woken to take his turn in making breakfast for the day.

Lucifer's eyes quickly snapped to attention at the presence of Barbatos, and flickered over to Satan who stood by the Butler at the entrance. He took the final sip of coffee before placing the mug back on the table, and stood to meet Barbatos and Satan in the doorway. Mammon's eyes shifted to the door, but he stayed silent.

"Barbatos, what is the matter? Any changes to the meeting plans for tonight can be-"

"The meeting is not of importance anymore, Lucifer. The prince requires you at his castle immediately. You needn't bring anything. It… it would be wise of you to have your brothers at the ready and in the vicinity." With only a moment's thought, Lucifer nods and looks to Mammon. The look alone is an order to get their siblings ready and to the palace ASAP, but of course the second born is absorbed by something on his phone, and misses his older brother's gaze completely. With a scowl, he turns instead to Satan, who walks away to carry out the task.

The fourth born knew that this could not be good news, but he did not yet know what to prepare for. Barbatos had said not to bring anything, so any weapons were not required meaning there was not a risk of a battle–at least not to that extent. However, when it was not for some diplomacy or student council issue, it was rare for Diavolo to urgently call for the presence and assistance of all seven demon brothers.

After narrowly escaping the kitchen without any pieces of him in Beel's stomach, Satan leads the way to the palace with his brothers in tow. They make quite the powerful group, but lack any resemblance of one. If he saw an angry otaku whining about his body pillow being thrown across the room, a hangry black hole with a sleeping little brother in his arms, a man waving to every reflection he could see, and a gremlin of a brother practically chasing a carrot on a stick, he would not be very intimidated. Satan was however, very amused as he gripped the 10 Grimm in his pocket that he promised Mammon once they reached the castle.