Is it forbidden to sit and go out with friends who frequently curse, swear, and use obscenities, some of whom also smoke? And is it forbidden to sit in cafes and places of entertainment and recreation due to the prevalence of objectionable acts therein?

A Muslim is prohibited from attending gatherings of disobedience unless out of necessity, or if capable of removing the evil. This is based on the Almighty’s saying: "And He has already revealed to you in the Book that when you hear the verses of Allah disbelieved in and ridiculed, do not sit with them until they engage in another conversation. Indeed, you would then be like them." (An-Nisa: 140). Thus, one who is present at evil is like one who commits it.

It is not permissible to sit with friends who commit acts of disobedience such as cursing, insulting, obscenity, and smoking, as long as one does not prevent them from committing the evil, unless there is a necessity for sitting. However, in situations where they do not commit sins, sitting with them is not forbidden.

A Muslim must choose righteous companionship that helps him obey Allah, and avoid bad companions.

It is not permissible to sit in cafes or entertainment venues where forbidden acts are committed at the same time and place, unless the sitter is in a place where he does not witness such evils. However, if sitting in a place where no evils are committed, then there is no harm in that.