The unnamed bridesmaid in You Exist Too Much (the novel by the Palestinian-American author Zaina Arafat) is a bisexual character, just like the unnamed narrator of the novel. Additionally, the unnamed bridesmaid is also Arab-American like the unnamed narrator.
The narrator and the bridesmaid meet at the wedding of the narrator’s cousin. They both experience a lot of prejudiced attitudes towards LGBT people in their culture; at the cousin’s wedding, the other bridesmaids and cousins mock this particular bridesmaid for assuming that she’s lesbian.
The narrator admits that she “felt guilty laughing along” at their homophobic mocking, but was scared that if she didn’t, the other cousins and bridesmaids would ” see through to [her] secret” (of being bi) and know that she isn’t straight. In fact, the narrator secretly sleeps with the bridesmaid one night.
The bridesmaid is 28 years old (10 years older than the narrator, when they have sex) and admits to the narrator that she is “seeing people everywhere. […] I’ve got someone in almost every major city.” The fact that she says she’s seeing “people” not “women” means that she is more likely bi than lesbian.