The Hazards of Working Together

I ran in to Dave in the hall at work. I was on my way to the bathroom, he was wandering around with a screwdriver set (I didn't ask why) we smiled at each other in acknowledgement that we recognise one another then he proceeded me through a door way. I almost reached out and grabbed his butt (it's not so much a sexual thing more of a greeting). Then I remembered that we're at work and that would not be appropriate. This is the third office we've worked together in (I know your shocked we're still together) and about the millionth time I've had to remember that the boundaries aren't the same as at home.