Bismillaah:

The prohibition of alcoholic drinks is one of the matters that is widely known and emphatically emphasized in Islamic law. Proof of its prohibition is found in the Qur'an and the hadeeth.

Allaah عزوجل said in the Quran:

" O you who have believed, indeed, intoxicants, gambling, [sacrificing on] stone alters [to other than Allaah], and divining arrows are but defilement from the work of Satan, so avoid it that you may be successful."

{ Surah Nisaa verse:90 }

And the Prophet صلى الله عليه وسلم said:

“ Do not drink Alcohol for it is the key to every evils .”

Takhreej:

{ Imam Ibn Majah in his Sunnan #3371 and graded as Saheeh by Imam Al Busaayri رحمه الله }

This means that if alcoholic drinks are prohibited, then sitting at a places where they are served or drunk is likewise prohibited.

Umar ibn al-Khattaab رضي الله عنه relates:

The Prophet صلي الله عليه وسلم said:

“Whoever believes in Allaah and the Last Day, let him not sit at a table where wine is being drunk.”

Takhreej:

{ Imam Ahmad in his Musnad #126 and graded as saheeh by Shaykh al Albaani رحمهم الله }

Another report:

" Whoever believes in Allaah and the Last Day, let him not sit at a table over which wine is being served.”

Takhreej:

{ Imam At Tirmidhi in his Sunnan #2801 and graded as Hasan by Shaykh al Albaani رحمهم الله }

The commentator on the hadeeth said: even if he does not drink with them, it is as if he is approving of their evil action.So it is not permissible to sit with them or to converse with them, even if one does not drink, because if he does that he is like a silent devil.

{ Majmu Al fataawa al Kubra }

*** And Allaahعزوجل knows best ***