Let’s look on the bright side. Hillary has, at some times in the past, had heterosexual affairs. (Vince and Webb, at least). She’s part of the heteronormative establishment!
I am not convinced that Hubbell was an “affair.” It was maybe more like a deal involving all parties to produce an offspring for Bill who is likely sterile to enhance his political profile. Too bad it was a girl that resulted. A boy that looked like Hubbel might not been regarded generally as ugly.
She realized that she needed a child because that would look good to what she considered the stupid redneck voters in Arkansas, and Slick wouldn't or couldn't make that happen.