Part 16: Rights of The Upright Scholars- [Etiquettes of The Student Whilst In The Sitting of a Scholar]: By Shaikh Muhammad Baazmool]
In The Name of Allaah, The Most Merciful, The Bestower of Mercy
Shaikh Muhammad Baazmool [may Allaah preserve him] said: In the sitting of a scholar, one should be aware of the following:
 One should be under the authority of the scholar, whilst sitting in the gathering.  One should not sit very far from the scholar nor very close when in the sitting in the gathering. [Ref 1]  One should make room for other students who want to sit.  One should not desire to speak, neither should he argue nor debate.  One should not start speaking until the scholar begins [and gives him permission].  One should not impose what is to be spoken about in the sitting without the permission of the Shaikh.  One should not speak after the Shaikh has spoken, unless given permission by the Shaikh.  One should not backbite anyone in the presence of the Shaikh.[ref 2]  One should not make the Shaikh perceive that he is tired [bore] or displeased.  One should not sit whilst not [desiring] an increase [in knowledge] or whilst having little concern for the sitting.  One should exercise patience when he experiences something defective from the Shaikh’s character or experiences harshness from him, because the Shaikh is [nothing else] but a human being [i.e. he is not perfect].
Source: [في قلب الحدث مقالات متنوعة – page 57 Abridged and slightly paraphrased]
Ref 1: Sitting close or far away from the Shaikh…see link:
Also remember that backbiting is allowed in six cases as stated by Imaam An-Nawawi [rahimahullaah]. See details in the link by Shaikh Muhammad Bin Haadi [may Allaah preserve him]: http://www.ajurry.com/vb/showthread.php?t=36254