Adult advice please!?

I'm pretty sure he is interested. He probably just umes you are not interested. He probably feels uncomfortable and unsure just like you. I would suggest going to his cubicle and talking to him. Maybe on a Thursday or Friday you should go to his cubilce and act like your stressed out with work and say "lets go get a drink after work." Or maybe ask him what his plans are for the weekend and if you both have nothing to do he'll man up and ask you out. Ultimately there is only so much you can do. As a man its his responsibility to be aggresive and pursue you. If not, he's going to end up being a wimp in your relationship.