I feel like any minute now my flist will scream at me to STFU with TSN.
Anyway...
Every fandom should have such sweet teen!angst stories.

Title: Unexpected Relations
Author: grim_lupine
Pairing: Mark/Eduardo
Rating: NC-17
Word Count: 28,000 words
Summary: [Step-brothers AU] It’s true, there’s remarkably little awkwardness between Mark and him. Maybe it’s because they’re both mature enough to work past any that might arise, for the sake of their parents. Maybe it’s because Eduardo can see that Mark is a better person than he seems to think he is, and Mark doesn’t care that Eduardo doesn’t always feel like being kind and giving, that sometimes he just wants to say exactly what he’s thinking.

The link.

On top of that, check PWP part