This is what I was told back in High School. It's when 2 men have anal sex and then one man cums up the other guy's ass. Then that guy who came sucks the cum back out the ass with a straw. Hmm.
Ted and Fred love to slurk each other.
Lurking while not doing anything in particular, or of use. Particularly applies to late nights, when thought is difficult.
Ted: Hey Mike, what're you doing up at 3 AM?
Ted: Oh. So you're like ... browsing 4chan?
Mike: Nah. Just slurking.