Regarding head rubs, I had an interesting situation. There was a woman from my company's DC office who would come the corporate headquarters several times a year for management meetings. I would be in those meetings and at breaks, etc., she would pass behind me and give me a quick headrub. Turns out I met her husband at the company holiday party and he shaves his head! She said she hoped I wasn't offended that she just found the quick rub to be irresistible.