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, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
The use of vulgar language is not forbidden; however, it is reprehensible to use it under normal circumstances.
On the other hand, using obscene (dirty) language is forbidden in its origin. We have highlighted the difference between the two categories in Fatwa 87384. So you should abide by this which is allowed to be used during intercourse and which is not.
It should be noted that it is better to abstain from such language (both kinds of language) in totality. The Maaliki scholar Ibn Al-Haajj wrote about the merits of abiding by the Islamic etiquette pertaining to sexual intercourse, “The husband should avoid what some people do such as snorting and using dirty language. When Imaam Maalik was asked about that, he considered it disliked and condemned it. Ibn Rushd commented that Maalik considered it disliked it because it was not from the actions of the righteous predecessors (Salaf).” [Al-Madkhal]
Allaah Knows best.