Swearing is the use of taboo language with the purpose of expressing the speaker's emotional state or communicating that information to listeners. Research suggests that bilingual individuals tend to swear more in their 2nd language than their 1st language.
Because they tend to think that swearwords in their 1st language have a stronger emotional resonance, & therefore, it is easier to utter taboo words in L2. E.g. Indians who speak Indian-English as a other language, tend to use more Eng swearwords than ones in their own language.
An interesting case is of the Mughal Emperor Akbar (1542-1605) who is believed to be bilingual in Persian and Hindi/Urdu ancestor language of that time. In Akbarnama of Abu al-Fazal, emperor Akabr used the Hindi/Urdu swearword gānḍū (= catamite, sodomizer). 
Dr. Tariq Rahman (2002) quotes '' When Akbar was about to kill Adham Khan he said, in Abul al-Fazl‘s words: Hazrat ba zaban Hindustani farmudand ke 'ai kandu' (i.e. gandu‘). (Translation: Akbar said in the language of India: Hey catamite / sodomizer‘).''
Italian traveler Niccolao Manucci (1638–1717) in his memoir about the Indian subcontinent during the Mughal era, mentions that Aurangzeb and Shah Jahan had full command over Hindi/Urdu of that time, & they frequently used Hindi swear words in their conversations & battle cries.
I have crowd sourced a long list of Hindi/ Urdu swearwords earlier. Here you can add more to the list -
