I’m just going to disregard the whole “is it weird” because other commenters have already answered that and say this:

Thank you for being supportive of your son like that, not making them feel ashamed or uncomfortable for asking, and actually showing them since you know how to do it.

My dad wouldn’t even show me how to properly shave my face even when I asked, gave me a one sentence explanation, and just went back to whatever he was doing. I had to learn from YouTube and trial+error.