Accidently clicked follow on someone's twitter profile - will they know?

Hi, this may sound stupid, but please bear with me.
I was having a look at some people's profile on twitter who I went to school with. I found someone that used to make my life hell but was a little intrigued as to what they were up to. I was looking at their profile on my iphone and accidently clicked "follow" then immediately clicked "unfollow". Will they have received a notification of this or was it too quick to have registered? It was literally straight after I pressed follow that i unfollowed.

Yes dear he will know. Your name will be in a list of his/her Followers.

Nope

I don't think so, because it doesn't on other sites. You should be alright. If it was straight away it wouldn't have accepted it because it was immediate. Like foll-unfollow. So it was interrupted. Plus it would be strange if you got a notification saying that somebody followed you, and then when you checked they didn't.

You will be found on his follower list!

I get notifications to say if someone has followed me on Twitter, but that is because I have my settings to do so. I'm not sure how it works if you follow then unfollow right away.

No. When you immediately unfollow him. He would not have received any notification. So you need not worry about it.

Yes, they will receive the notification.

They Won't Know Unless They Have Email Notifications Turned on Than They May Get a Email About it But Thats About It Other Than That They Won't Know They Won't See it

If they have notifications enabled to inform them when someone follows, they will get a notification email from Twitter. So in that case yes, they will know.

No, .seeing as you immediately unfollowed him, he won't receive any notification.