Foreign Thriller/Crime Film in Which Man is Forced to “Pleasure” His Own Brother at Gunpoint.

I saw this movie in an arthouse theater probably in the late 1980s to early 1990s. It was not in English and may have been French. The only scene I remember is a man has gotten in trouble with mobsters (owes them money or didn’t complete a job or something), so they bring him to a carpark and then produce his brother from another car (maybe from the trunk/boot). Both are grown men, mid-thirties maybe. At gunpoint, they force one brother to perform oral sex on the other. As the passive brother climaxes, he is weeping. It was a thriller/crime film I think; definitely not pornography. Needless to say, the scene was very disturbing. No one seems to recognize this film, though I would think that scene would stand out.