How to add relations belween content types and user using simple link/button in drupal 7

My project contains two content types:- Professor and Lecturer.
Here the users are student so students can log in using their own credentials.

Now I want to show up a button/link with Text "Follow Me" in Professor & Lecturer Content Type.When User/student will select the link/button then the corresponding Lecturer/Professor will be attached to the student profile and will be visible inside their home page. Similarly that student will be visible in Teacher/Lecturer.

I look at The "Relation" Module in Drupal 7 but my use case don't need to display too many things in the widget. There should be a simple button/link which relate user and content type.

Need your help on this.