Dive into your creative stream
(Fav - least fav)
Guilliman x Angron - Pure Hate fucking. No real kink, barely any after care. The only foreplay is an argument, or more often than not, it's just Angron trying to shut Guilliman up when he rambles about taxes
Magnus x Jagathai - In my opinion, the most wholesome of all the ships. Like they might get a bit freaky in the bedroom here and there but usually no more than light bdsm if that. They love being flirty and just being around each other. Magnus reads to Jagathai while the Khan works on his bikes
Fulgrim x Ferrus - A classic, the ship that got me into shipping the primarchs. Literally femboy x Muscle Daddy. Fulgrim has every kink and fetish under the sun, and Ferrus indulges him because he loves to make his brother happy. They also love going out on dates and being cute together.
Horus x Sanguinius - I know I'm gonna catch heat for this one. Sorry, @moociaoafterdark . It's not my least favourite, but I gotta admit it's like a good in-between of Fulgrim x Ferrus and Magnus x Jagathai. You have the wholesome playful interactions with a bit more spice than Magnuthai. Like Horusang aren't trying everything in Fulgrims playroom, but they are definitely in a sadist x masochist relationship.
Dorn x Perturabo: . I wanna say hate fucking but like it's only that for Perturabo and even then sometimes. They're both their own brand of autism and they'll get on each other's nerves, but honestly, as a couple They're pretty "solid".
Konrad x Vulkan: Honestly? This is like the last ship I'll actually push for. Even then, I'm on the fence. I think these two are a wombo combo of Angron x Guilliman and Sanguinius x Horus. Like Vulkan being a pure masochist who regeneration from anything x Sadistic horrific Konrad who's constantly coming up with more torture methods to use on Vulkan. Vulkan is more than willing to take the pain if it means curbing some of Konrad's more vile urges.
Alright, these next two ships are honourable mentions. I could take or leave them. I don't really ship SHIP them, but I think their relationships would be funny:
The Lion x The Twins- Both Legions and primarchs have their secrets and play things close to the chest. I can totally see El Johnson treating his relationship with the twins as his dirty little secret. He would also be one of the only people to know their are two, not one. You also get to throw in some Twincest free of charge.
Leman x Corax - I'm mainly doing this one for two reasons Loud bombastic jock x quiet sulky goth/emo and reason two is the relationship between Corvids and Wolves. It's one of the most iconic symbiotic relationships in the wild. I don't really have more than this.
Finally, you're no doubt to notice I've left 2 out(no, not the missing 2). Well, for them, I have my own personal headcannons.
Lorgar- Huge fuckin simp for Emps but is kinda heart broken when he finds out he can't fuck God. So he goes to whichever of the couples will have him for a threesome sometimes. He's almost as kinky as Fulgrim but is unabashedly the most deviant of all the brothers. Sometimes Leman obliged and cucks Lorgar while spitting on him. Sometimes Horus and Sanguinius need a whiny subby blood bank. Lorgar is just a massive pervert.
Finally the best for last! My fav primarch: Mortarion!!! - so I put this in the tags of my last post. I totally see morty as Ace, especially Aro/Ace, but he's not sex adverse. In fact, he loves masterbating and has a few kinks that would make Fulgrim blush. He's truly oblivious to his brother's relationships, but he loves to get behind closed doors and not shower for weeks while working it to his own rancid smell. He might torture some serfs with his smell while forces them to eat him out. (What? You thought Sanguinius was the only Trans masc?)
This is what inspired the script above.
Emps after finding out the Primarchs are doing the hanky panky:
(This story is interchangeable, but I'm using the female Primarchs from the Femmarch au)
*The Scene: The Emperor has called his daughters to an impromptu private council. None of the sisters know why, but it's pretty clear how serious this is*
Emps: Listen, im going to make this clear and concise. *he narrows his eyes and scans over his daughters* I know.
Horus: Know what, father?
Emps: Don't Bullshit me! I KNOW...
*All the sisters begin looking around awkwardly at each other or shamefully away from each other*
Emps: It was brought to my attention, and while truthfully, I couldn't care less what escapades each of you get up to in your own time. If these activities were to come to light, it would set the wrong example for our Imperium. So, if all of your "relations" are to continue, ensure they are kept quiet.
Fulgrim: *evil smile* That means you two. *she points to Guilliman and Angron*
Angron :What do you mean, us!?!
*Angron raging and nearly leaps across the table at her sadistic sister. Guilliman holds her back*
Fulgrim:*laughs* Oh, come on! Last night, I swear all of Terra could hear you two from orbit.
* Both Guilliman and Angron sit back, blushing ashamed*
Khan: You're one to speak Phoenician. You and Ferrus are practically inside one another any chance you get.
Fulgrim: Ahh, just like you and dear Magnus when you lock yourselves in the library for "Special Research"
Sanguinius: Alright, I think we've all had our fun. Now--
Fulgrim: I don't wanna hear any lectures from you! We all know who actually holds Horus' leash.
*Sanguinius sits back down flustered. Horus leans over, trying to comfort her*
Emps: Alright, Enough! As I said, I was made aware of all your escapades. This means I DO NOT want to HEAR NOR SEE anything outside of your private chambers. Do I make myself clear?
*All the primarchs nod in acknowledgement, except Mortarion*
Mortarion: *confused* Wait. You're all fucking?
---*End scene*---
(This is basically my scripting process when I make comics)
(This story is interchangeable, but I'm using the female Primarchs from the Femmarch au)
*The Scene: The Emperor has called his daughters to an impromptu private council. None of the sisters know why, but it's pretty clear how serious this is*
Emps: Listen, im going to make this clear and concise. *he narrows his eyes and scans over his daughters* I know.
Horus: Know what, father?
Emps: Don't Bullshit me! I KNOW...
*All the sisters begin looking around awkwardly at each other or shamefully away from each other*
Emps: It was brought to my attention, and while truthfully, I couldn't care less what escapades each of you get up to in your own time. If these activities were to come to light, it would set the wrong example for our Imperium. So, if all of your "relations" are to continue, ensure they are kept quiet.
Fulgrim: *evil smile* That means you two. *she points to Guilliman and Angron*
Angron :What do you mean, us!?!
*Angron raging and nearly leaps across the table at her sadistic sister. Guilliman holds her back*
Fulgrim:*laughs* Oh, come on! Last night, I swear all of Terra could hear you two from orbit.
* Both Guilliman and Angron sit back, blushing ashamed*
Khan: You're one to speak Phoenician. You and Ferrus are practically inside one another any chance you get.
Fulgrim: Ahh, just like you and dear Magnus when you lock yourselves in the library for "Special Research"
Sanguinius: Alright, I think we've all had our fun. Now--
Fulgrim: I don't wanna hear any lectures from you! We all know who actually holds Horus' leash.
*Sanguinius sits back down flustered. Horus leans over, trying to comfort her*
Emps: Alright, Enough! As I said, I was made aware of all your escapades. This means I DO NOT want to HEAR NOR SEE anything outside of your private chambers. Do I make myself clear?
*All the primarchs nod in acknowledgement, except Mortarion*
Mortarion: *confused* Wait. You're all fucking?
---*End scene*---
(This is basically my scripting process when I make comics)
Juno (Fem Guilliman) The Fem Primarch of the UltraMOOrines is dominated by her dear sister, Atlantia (fem Angron) Lioness of Khorne.