I know, I know, relationships and work don't mix. We flirt with each other at work and I know he wants some but I can see his sensible side holding back. What if I don't want a relationship? What if I just want a little bit of a fling? Or a friend with benefits? How do I even begin to approach this with him when we have that professional working relationship going on?
I'm not asking whether or not I should, I'm asking how to get it.
First, screw the work/relationship nonsense. There's a difference between a career and a paycheck, one major distinction being paychecks are interchangeable, as long as they don't bounce. A great romance, by contrast, is unique.
How to get it? The ancient ritual: drinks after work, dinner after drinks.
You already stated you know this, but you should not be pursuing a colleague! Yes, I just had to say it. :P
If you really want to pursue something invite him out after work. Start building a friendship outside of work and spending some alone time. A warning though; if he is hesitant to do anything with you outside of work just back off and drop it. You don't want to be the crazy co-worker that is seen as stalking him.