Batman and Catwoman
What is it with Batman and his propensity for women of dubious moral fiber? From Poison Ivy to Talia al Ghul, Bats has an inexplicable appetite for bad girls, though there hasn't been a tryst more questionable than with Catwoman. And it's not as though this is a one-sided fling; the two have sneaked a lengthy smooch or fifty in the past, indicating that, yeah, Batman and Catwoman have a thing for people in mammalian superhero guises. In the alternate universe of Earth-Two, the pair went as far as having a child that followed in her father's righteous footsteps: Helena Wayne a.k.a. Huntress.