Is it okay to laugh of sounds coming out of another mans behind? Muslim and non-muslim?

All Perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as that of his family and all his companions.

The Prophet has prohibited laughing at the sound of passing gas from others. ‘Abdullaah bin Zam'ah said: "The Prophet forbade laughing at a person who passes wind." [Al-Bukhari]  He also narrated that he heard the Prophet delivering a sermon in which he advised them not to laugh when somebody breaks wind saying, "Why should anybody laugh at what he himself does?" i.e. why should someone laugh at something that no human being is immune from?

Imaam Al-Bukhari classified the first narration under the following title, "The chapter of Saying of Allaah: {O you who have believed, let not a people ridicule [another] people; perhaps they may be better than them; nor let women ridicule [other] women; perhaps they may be better than them. And do not insult one another and do not call each other by [offensive] nicknames. Wretched is the name [i.e. mention] of disobedience after [one’s] faith. And whoever does not repent — then it is those who are the wrongdoers.}[Quran 49:11].”

Imaam Al-'Ayni said: 'The relevance of the narration to the verse is that laughing on passing wind by someone implies mocking and ridiculing him.'

Moreover, the ruling of prohibitions of laughing applies to both Muslims and non-Muslims alike since the text of the narration is general and does not differentiate between a Muslim and a non-Muslim.  

Allaah Knows best.