It’s never too much friend.
Steve/Tony, matching soulmate markings.
Tony never really had much faith in his soulmark. Sure, the thought of having someone out there just for him was nice, but after forty years of life throwing its shit at you the novelty starts to wear off, and the soulmark becomes yet another fairytale.
Afghanistan happens, and the shrapnel embeds itself right above his heart, right onto his soulmark, ouch. Next thing he knew there’s a gaping cavity in his chest and a night light is replacing the mark people spend so long obsessing about.
To Tony though, it’s almost a relief. No more looming thoughts about his other half restraining him, no more mark as a constant reminder.
That is until, one fine day, Captain America rushes into his lab and demands to know what his soulmark looks like.
"I don ave one." He says around the screwdriver currently clenched between his teeth. Steve frowns.
Tony spits the screwdriver out, straightens and points at his chest. “I used to have one, here, you see?” He says, tapping his arc reactor. It makes a slightly hollow sound that Tony compares to his love life.
Steve looks…relieved? “Oh.” He says, before fumbling around and picking up a notepad and a pencil Tony had left lying around, scribbling something onto it. He holds it up.”Did it use to look like this?” he asks, looking hopeful.
The drawing is of a star, surround by swirls and loops. The drawing is also the exact same as what used to be Tony’s soulmark.
"…Yeah. How did you?"
"I didn’t realize at first, but then I saw your arc reactor." Steve says. When Tony simply gives his a confused look, he starts taking off his shirt.
"My soulmark used to look like that too, you know, but when I got out of ice it had changed." he says, and turns around.
And on the back of Steve’s left shoulder, is a outline of the front of Tony’s arc reactor.