This happened with a new graduate student in my department. I am a faculty member. I asked him if he preferred to be addressed by the long or the short version of his name. He said that only his mother calls him by the longer version. So, I think, the short version is what you go by. But, he continues, in a dreamy voice (mind you, this is in a seminar setting), because his mother calls him that, he finds it so soothing and gentle, so maybe I should use that one.
I was hard pressed not to laugh (but did manage it). The other students, who know me better (and would never consider classifying me as ‘just like mom’) all looked shocked and horrified. Does he ask the male faculty members to use his dad’s name for him? I strongly suspect that he would never do that.