The Cook, the Thief, His Wife & Her Lover(1989)

Overview:

When churlish mobster Albert Spica acquires an upscale French restaurant in London, he dines there nightly, effectively scaring off the clientele with his bad manners. His wife, Georgina, is especially disgusted by him, and soon begins an affair with regular guest Michael. Despite their best efforts to keep it secret, Spica learns about their trysts, and he plots a terrible revenge.