Septiplier and Darkiplier x AntiSepticEye
When Mark and Jack confess their feelings for each other , their dark halves come out to play. Little did they know, their dark halves liked each other too.
Note: Anti-jack and Darkiplier are nicer than in some other fanfics. Anti-jack mainly knocks things over and steals food from the fridge. Dark is less nice than anti-jack but still nice. Jack and mark know about their own (physical formed) dark selves but not each other's. Dark and Anti-Jack can also not be in a physical form, but still interact with things.