Basically, you have a mark on your body (a symbol or image of some sort) that represents your soulmate. Generally it's no bigger than a hand.
Peter's mark is huge, but it's more of an impressionist painting than a "proper" symbol, instead swirls of tonal reds. Maybe it even goes on to his face some, requiring the full mask. Peter can't even imagine the sort of person that it represents.
Then he meets Matt, and can.
+ Matt's mark is similarly humongous ++ They have a whole meet cute in a coffee shop or something +++ Matt can't believe his soulmate's like 19, this is absurd
Matt/Peter Parker, Soul Mates AU
Peter's mark is huge, but it's more of an impressionist painting than a "proper" symbol, instead swirls of tonal reds. Maybe it even goes on to his face some, requiring the full mask. Peter can't even imagine the sort of person that it represents.
Then he meets Matt, and can.
+ Matt's mark is similarly humongous
++ They have a whole meet cute in a coffee shop or something
+++ Matt can't believe his soulmate's like 19, this is absurd