I don't care about seeing other people's comments, but I'd like to be able to prevent people seeing my comments on other peoples' posts unless it is a mutual fr

I don't care about seeing other people's comments, but I'd like to be able to prevent people seeing my comments on other peoples' posts unless it is a mutual friend or something. No matter what it is I comment on, a news article, or a group post, and my dad (and I am sure other FB friends) see it even if we aren't connected to the same groups and sites.