Well, to portray it respectfully in erotic fiction, it should avoid stereotypes. Instead of relying on clichéd ideas about lesbians, show the unique relationship of the characters. You could explore their insecurities and how they overcome them together. And the sexual elements should be part of a broader story of their relationship development. For instance, a touch or a kiss can be described as a significant moment in the progression of their feelings, not just a sexual act on its own.
One way is to focus on the emotional connection first. In many good portrayals, the initial attraction between the two female characters is based on a deep understanding and shared interests. For example, in some well - written stories, they might bond over a love for art or a common cause. Then, when it comes to the physical aspect, it can be described in a more tasteful manner, like using soft and evocative language rather than being overly explicit. Also, respecting the characters' identities and not objectifying them is crucial.