In the article, they address their lesbian fan base:
"From the beginning, that lively chemistry – along with the fact that the characters can't maintain steady relationships – has some fans wondering whether there was more between Rizzoli and Isles than just dusting for fingerprints. [...] Alexander just smiles. "There's nothing gay about them," she says. "What's gay? That Jane has a raspy voice?" Still. Harmon admits they do play up the tension sometimes. A poster for the new season features the women languidly stretched out together on a picnic blanket, for example. "Sometimes we'll do a take for that demo," Harmon admits. "I'll brush by [Maura's] blouse or maybe linger for a moment. As long as we're not being accused of being homophobic, which is not in any way true and completely infuriating, I'm OK with it."
Writer Janet Tamaro previously told TV Guide:
The lesbian theory endlessly amuses me, and it amuses the cast. Rizzoli and Isles have been heterosexual from the first episode, though there is no way I would want to interfere with my viewers' fantasy lives.