A/n: The prompt I got was "Levi being a jealous little shit and leaving kissmarks everywhere on Erwin's body" yet it evolved into something more obsessive-possessive.
When all of your life is filled with racing towards an early death, you have nothing except your own willpower to latch on. You grow numb to relationships after seeing every one of your friends and accomplices fall, leaving nothing but bloodstains to be scrubbed out.
Yet Levi was desperate to fill the numb void that was left behind by being alienated, put on a pedestal just for staying alive, to fix what he had become. Humanity's strongest didn't have the luxury of human errors.
So he latched onto the only other person who was put on a pedestal higher than his own. In some ways, Erwin Smith was all he had. And Levi had no intentions of letting go.
Levi could feel it in his bones the best while sinking his teeth into Erwin's flesh with a clear intention to leave a prominent mark. Seeing it afterwards, even if just a glimpse, made him more alive, gave a purpose.
Erwin never commented, no matter how uncomfortable it would get with Hanji's questioning looks and Petra's obvious staring which was quickly followed by shy diversion of eyes, he never complained.
He didn't have to ask, didn't really want a confirmation of how it went deeper than just them, how ridiculously personal it was to Levi, like his life depended on it – seeing that something, someone belonged to him and him alone.
Wrapped up in careful jealousy, so no one would know and dare take it away, Levi sank his teeth into the flesh of Erwin's neck, biting none too gently before sucking and soothing with gentle swipes of tongue.
Collarbone, where neck connected with shoulders, throat – everything was littered with deep purple and angry red marks Levi left at every opportunity.
Erwin had even gotten used to the man sneaking up behind him, pulling down the collar of his shirt and nipping, biting, sucking while others were simply engrossed in something else. It was torture for him not to let a single sound out and endure questions about his flushed cheeks later on.
"Don't forget whom you belong to." Was quietly whispered against his ear, lithe fingers brushing against the sensitive skin of his neck.
As if he could, with all the reminders mapping his skin.