I hate when coworkers come in with their new born babies for a show-and-tell. I never know what to say.
I usually find something else to do during the "show-off" period, but then someone will always ask where I was which only introduces the awkwardness I was trying to avoid. It's like they are insinuating I am hiding or avoiding the "situation." I mean, I guess that's technically true, but I don't think it is right for people to think that way since that's not really my intention... exactly. Besides, having a baby should be a private event.