Just give them a really simple answer and move on -- "Nope, my choice to use silver has no reflection on you using stainless. Bean dip..." Their insecurities and imagined slights here are not your problem. I wouldn't even get into a discussion. Simple answer, move on because there's really nothing you can do, other than make yourself really miserable and second guess yourself.
DF will, more than rarely, misinterpret something I've said; he'll be about as off as your friends. I've learned to just tell him, often, that my tone or words do not have the meaning he's interpreting, and I'll leave it at that. I've found that analyzing why he feels this way just leads nowhere (doesn't mean I never discuss these things with him but there are a few times that his interpretation borders on the ridiculous that I just won't bother with because he just needs to get over himself after I remind him that there's no hidden meaning to what I said, same as your "friends").