Why does no one consider bisexuality?

A lot of people are upset about the fact that Ellen had sex with a man, and I actually agree, it was annoying for many different reasons. But the thing is people are calling both Ellen and Jill lesbians, when the truth is, it is NEVER actually said what their sexual orientation is. Not only that but the relationship is so vague that it's hard to tell if they were lovers, or just VERY close and dependent friends and roommates. But if you want to get realistic about it and pick a sexuality for them, then I'd say that Ellen was bisexual and Jill was the gay one.