No, Adolf Hitler never cheated on his heterosexual life partner/ wife Eva Braun.
Below is a delightful study of the women who surrounded Adolf Hitler. The report itself is undated and unaccredited but appears to be a study conducted by the US military, probably the US Army, sometime after the conclusion of the Second World War.
Hitler's Women: A Study of Them By the US Gov.
The report, as posted here, is nine pages with a single page memorandum attached to it. However, the last page of the report ends abruptly which shows that this report was at least one page longer. However, the nine pages posted here are all that made it to the National Archives for preservation.