What happens if you follow then unfollow someone on Instagram?

[Adelaide :3]

I know a friends Instagram username and password, and she knows I know it.
Well, I like this guy but his Instagram is private and I want to see his stuff, so I'd have to follow him.
I don't have an Instagram, so I can't follow him
Would she know if I followed him for a few minutes then unfollowed him? She doesn't know I like him and don't want her to find out.
Haha don't lecture me on how it's wrong, just tell me if yes she would know or if no she wouldn't. Like, do people get a notification to their own account when they follow someone. I don't care if he sees that someone followed him then unfollowed him. Thanks(:

[sissy]

No. The other person would when you followed them, but you won't.

[MATahir]

It is all the time wasting task

[Midnightturkey090]

You can unfollow, but he would know most likely

[Bobby]

no..its like facebook..u know when they follow u but u dnt know when they un follow u... have fun