I'd like to point out here that the _characters_ on Daria, and by extension their sex lives, are every bit as real as the _characters_ in any work of fiction. Their _bodies_ are being animated rather than provided by live actors, but that doesn't change the reality of the _characters_.
After all, the actors and actresses in a live action show are _not_ the characters. Their loves and hates are not necessarily the same as their characters, nor (unless this is outright porno) are their sex lives necessarily in any way similar.
Daria is Daria, not Tracy Grandstaff. Jane is Jane, not Wendy Hoopes. They have their loves and hates and, yes, lusts, as real as those of any other fictional characters, and independent of both the ink that draws them and the actresses who provide their voices.