That au that was going around Tumblr: I got drunk and broke into my friend's apartment to sleep it off except hey when my friend get a cat, crap this isn't my friend's place but hey you're pretty cute *eyebrow waggle*

Also truth serum! Always accidental truth telling.

And shouty bickering and one them yells that he loves the other one actually, and things get really quiet.

OH and Chuck or Zelenka is running a pool for when they finally get together and they find out and ruin it (by making sure no one wins or by teaming up with someone, making sure they win, and splitting the prize)