I had a "work wife" once. I being a heterosexual male, her being a homosexual female, I honestly couldn't imagine what could go wrong.
One day, shortly before the end of our shift, we decided imbibation of ethanol containing beverages was in order. In an effort to be conscientious, I called the GF and asked if we had plans that night(she had a habit of scheduling things and not telling me). We did not; in fact, she was working that not. "Ok honey, I'm going out for a drink with Allie after work. See you tomorrow."(made sure to mention whom I would be drinking with). No objections. The next day, a picture of the two of us, fully clothed, not in physical contact, hardly discernible as even knowing each other is posted on Facebook. Calamity ensues, predictably.
I no longer engage in affectionate gestures, verbal or physical, with women I'm not affectionate towards. I also no longer have Facebook. Which is more beneficial to me in the long run I'm not sure, but both lifestyle changes are hear to stay.