Prior to line fifteen, in Adrienne Rich's poem "Living in Sin," a woman is depicted as thinking about how the studio she shares with her lover "would keep itself." Instead, the studio is seen in less than perfect order. After line fifteen, where "meanwhile"
appears, the lover is seen sitting at an out of tune piano, getting disgusted at the piano's tune, and leaving for cigarettes. When the lover leaves, the woman begins to clean the studio.
The simultaneous occurrences are the woman questioning the state of the apartment and the lover plucking away at the keys of the piano (and then leaving the studio). Both of these occurrence can be looked at as similar and in opposition to each other.
First, both the woman and the lover are disgusted by something in the studio. The woman is disgusted by the state of the studio and the lover is disgusted by the state of the piano.
In contrast, the woman seems to be concerned with something that both she and her lover should be concerned with: the state of the studio. Instead of having any concern for the studio (which they share (assumed)), the lover is only concerned with the piano.