I wear around my younger brother and my cousin a lot because I wear and use primarily on the weekend, I'm sure they have noticed as theres times I wear loose fitting clothing and times I have fell asleep when I didn't intend to (hard working man here, so exhaustion is a guarantee at times) , they have never said anything except for my cousin once when he was drunk, but otherwise they don't say anything.
I have also worn and used them around my mom, she sometimes feels like mentioning how sometimes I "walk funny" (thick diaper waddle really) or will ask if I'm wearing (even though I don't usually wear a diaper around her, but sometimes it seems unavoidable).
I really dont why friends and family should care, but in that regard if friends don't still act like they are your friends after they find out, then you dont need them and you are better off without them.
As for family, it can be risky business to wear and use around them if there is any possibility of it being a bad thing if they find out, like if they might kick you out.
Luckily since I pay plenty of money out in bills the house I'm living in is equally mine as it is my moms, we have been living in it the same amount of time and paying bills and trying to get ahead is a "partnership" of sorts, with the goal of both of us making it and when the work week is done she is out of town with her boyfriend anyways, so then it's just me, my younger brother, and sometimes my cousin.
I have only told one friend and he took it well and we still talk and he took me out to buy things on black Friday (technically Thursday though), and that was the only day I wore around him (I dont think he knew because in the store we went our separate ways and of course he was distracted about buying his own stuff) , didnt even wet the diaper until I was back home (didnt need to).
If I put on a diaper I try my best to make it almost impossible to tell for sure (unless somebody is looking for it) and of course i intend to use it (but only wet, i dont mess unless I'm away from other people)