Easy to help out

What is the male equivalent for the word Mistress? Why in the article about the actor, Sir Michael Gambon do they say that he is having a second child with his Mistress, However, they fail to say; "the Adulterer Sir Michael Gambon." Double standard me thinks. There are tons of derogatory and maligning words for women and oh so few for men, or when referring to men who like to sleep with lots of women, it's Lothario, oh so romantic compared to the female equivalent; slut.
The libraries in Ohio are threatened with a fifty percent budget cut brought to you by the state. There is a lot of waste where I work, a lot of foam on top kind of maneuvering around and cashing huge paychecks. But, somehow I know all of that will be justified and they'll end up laying off some clerks and those of us who actually do what employees of a library are supposed to which is help people rather than just tell them what to do.