I smoked with my mom once back when I lived with her and her crack-head ex-boyfriend. She was at a rough point in her life than using crack and vodka on the daily, so she would let me have massive house parties and she'd always end up in the living room smoking and drinking with me and my friends as the party would wear down. I'd also give her pot when, I didn't know it at the time, she was craving some crack. I guess it would help her calm down.
My mom has since cleaned up her act and I haven't smoked with her in years. She drinks socially with her new husband and has overcome her crack addiction. Her being addicted to crack kept her real close to me when I was battling my addiction to heroin. I think she could relate to me since she was also a slave to addiction at one point in her life.
As for my dad, I haven't talked to him in years and don't know if I would enjoy smoking with him. I used to openly talk to him about smoking and tripping on acid and he's a regular hippy from the 70s so he used to tell me about tripping on acid nearly everyday back then. Maybe when I reconnect with him I will smoke with him, but right now I am not worrying about that.
-legz