Get rid of a Twitter follower?

[Trail Gardner]

So I know it's weird, but I HATE being followed on Twitter by the people I know. Like, most of them are fine, but they get all up in my business, and it drives me insane. Anyway, someone that I know followed me the other day, and I immediately clicked "block." However, this person is still on my followers list. I want to know how to get them off. Like, are they still seeing my stuff? Do I need to watch what I say? I need a little help. :/