two things...

Firstly:
You should never make a gentle person angry, because they are much more likely to fuck your shit seriously up than a combative person.

Secondly:
I can't find this frickin' fanfic and I really, really want to reread it.  ARGH.

Help?  It's a Smallville fic (shut up), Clark/Lex, it's set when Clark is in college, he's being roommates with Lex and Lex spends most of the fic incredibly confused.  And gives up and jumps Clark when he brings cookies to the apartment from Smallville.  Or something.

EDIT:
Found it!