A lot of fic has Eddie introducing Steve to Corroded Coffin, and that's great! But how about -
Steve and one of the other members of CC stumble into being friends. Maybe one of them is secretly a sports fan, or their parents know each other so they get forced to interact at events. They get to see first hand that Steve is working on being a better person, but they both agree not to advertise the fact they get along.
Eventually something happens that forces Steve into interacting with the whole group, and Eddie doesn't know how to deal with the fact one of his oldest friends has been hanging out with Harrington. Who is a lot nicer than they used to be, and a badass, and good with kids and - oh no.
Steddie, Steve Accidentally Befriends Corroded Coffin
Steve and one of the other members of CC stumble into being friends. Maybe one of them is secretly a sports fan, or their parents know each other so they get forced to interact at events. They get to see first hand that Steve is working on being a better person, but they both agree not to advertise the fact they get along.
Eventually something happens that forces Steve into interacting with the whole group, and Eddie doesn't know how to deal with the fact one of his oldest friends has been hanging out with Harrington. Who is a lot nicer than they used to be, and a badass, and good with kids and - oh no.