Think of worms. It does not mean they do not have sex. Instead, it means that they try to dominate each other and fertilize the other. I think Oola was about to be eaten or she was about to get squeezed by the tail.
hmmm... I've always thought of Jabba as more of a slug, but worms reproduce similarly anyway. When they mate the more dominant partner becomes the male and the less dominant the female. I agree Oola was either about to find herself in a sexual encounter with her master or about to become Jabba's next snack.
Well the actual definition of hermaphrodite is not a lack of sexual organs but having both male and female organs. Hutts actually can change their sex at will, the reproduction advantage being that if there is a shortage of a certain sex they can even the population. Jabba is often referred to as he or him so I would guess like most hutt's in power he is male. This, unfortunately for Oola and his other slaves, would also mean he would have a male sex organ.
Haha, sorry for the long explanation. You might call me an "expert" on the hutt's reproductive bilogy.