as if she had "oil wells / Pumping in [her] living room." Though others might expect her to laugh quietly or politely, to walk softly, as one who is subservient or submissive might; she, instead, conducts herself as though she is very important—because she believes that she is very important and valuable. And so she repeatedly compares her behavior to the behavior of a person who owns things of great value: gold mines, oil wells, or diamonds. When she asks readers if it bothers us that she dances "like [she has] diamonds / At the meeting of [her] thighs," she insists that her womanhood, her femaleness, is of great value, despite how often women are oppressed or denied a voice, especially black women. This speaker doesn't act or talk or dance or walk the way white America might want her to; instead, she recognizes her value and she owns it proudly.

When calling her womanly parts “diamonds,” the speaker is emphasizing her sexuality and pride in being a woman.

The context of the poem is how a woman can continue to bounce back after being beaten down.  This can apply to a black woman or any woman.  The poem is an inspirational one, in which a woman takes pride in being a woman and continuing to “rise” when beaten down.

Does my sexiness upset you?

Does it come as a surprise

That I dance like I've got diamonds

At the meeting of my thighs?

The key to interpreting this stanza is the first line.  When the speaker asks, “Does my sexiness upset you?” she is talking about being held back by men, or even by other women.  She is proud of who she is, and does not hide it.  This makes some uncomfortable, or surpises them, including people who would objectify her.  She sees value in being a woman.