Popular vlogger Arielle Scarcella -- known for her YouTube series "Lesbians Explain," in which a panel of lesbians take on a variety of topics from "How Two Girls Have Sex" to "Why Straight Girls Love Lesbian Porn" -- has taken on an important undertaking, with fascinating (if not entirely scientific) results. Her inquiry: Why do straight women prefer penetration, while lesbians overwhelmingly prefer oral sex?

Scarcella did a bit of background research in the weeks before she released her new "Straight Girls Explain" video, asking 500 of her straight-identifying female viewers and 500 lesbian viewers whether they prefer oral sex to penetration. She found that while 55 percent of straight women preferred penetration, just 25 percent of lesbian viewers felt the same. So, for her follow up, Scarcella tried to figure out why.

According to the "straight girls," there could be any number of reasons for the disparity, but most have to do with social construction. A few common themes emerged in the descriptions: many of the women who have sex with men and prefer penetration felt that oral sex requires a greater level of vulnerability, and that to receive pleasure without giving it in return is uncomfortable. As Scarcella puts it in her analysis of the responses, "straight women are very uncomfortable with the idea of receiving sexual pleasure without giving it ...