Seeing how many of you refer to your Dad as "Old Man" I have an "Old Man" story to tell. You have to know my Dad to understand but here it goes.
My Dad was a plumber, pipe fitter, iron worker, race car driver, beer drinker, and one bad ass in the late 50's, 60's, and 70's. He fought a lot and his hands were huge, like bricks. My parents were divorced when I was less than one so I wasn't around my dad very much as a kid but more in high school. Anyhow, one day when I was in high school ('84-'85) me and a friend were at my Dad's car lot, where I worked detailing cars. My friend was telling a story about his Dad. My friend kept saying "Me and my old man"..."my old man this" and "my old man that",,,,on and on. As soon as my friend walked out the door, my dad gets up and grabs me by the shirt and pulls me towards him with his left hand. He makes a fist out of his right hand and puts it on my face and says, "See this fist son, I can black both your eyes, break your nose, and knock your teeth out with one punch boy. If you ever call me "Old Man" like your friend just did his Dad, that is what I will do. It is rude and disrespectful. You understand me?" I nearly *s-word myself. Prior to this day, it never crossed my mind to call him "old man". Needless to say, it never has.
Anyway, I think it is disrespectful to call your Dad "old man". Not because it is, but because my dad says so...lol. If I hear somebody call there dad "old man". I think "Oh God, where is my dad, I hope he isn't hearing this"...lol