Workplace situation

I'm a bisexual female who is currently in a relationship with a woman. I'm out to friends and family, but not to my employer or people associated with my job. I work as a home health care aide for an agency. I don't intend to be doing this job for the rest of my life. It is more interim thing until I can find a better job that is related to my college degree. In the past, in previous jobs I was dating men back then, but I never told anyone back then that I'm bisexual. In the past couple of years, I've become a bit sensitive to homophobic and transphonic comments. The reason I'm sensitive to the transphobic comments is because I'm close friends with transwoman.

Anyway, one of my clients is a man with dementia who lives who with his wife. Both are in their early 60s. I like the wife quite a bit and I have never told her about my girlfriend or my bisexuality. She once said that she didn't have a problem with gay people. But she has used a Spanish derogatory word for gays and lesbians before and she tends to believe that all lesbians and gays are butch women and effeminate men. Her three grandchildren arrived at the beginning of June to stay with my client and his wife for the summer. The grandchildren are a 15 year old girl, 12 year old girl, and a 5 year old boy. The kids come from a bad situation with their mother and while they aren't always rude, they can be never inconsiderate and they make a lot of homophobic comments which the grandmother says nothing about. They have made transphobic comments too. I'm always uncomfortable around them because of the comments and one of the girls made an insensitive rape joke a few weeks back. Yes, I know the kids are still young and don't know much about the world, but I just feel uncomfortable and in a way mistreated.

Has anyone been in a similar situation with their workplace? I have thought about the possibility of coming out to them, but my bisexuality would likely be misunderstood and I've thought about coming out to my supervisor and explaining the situation to her. Any advice is welcome. As soon I find another job I will quit this one right away and the agency I work doesn't require a two week's notice. So basically, if I got a new job on Monday, I could call in and quit right away without a two week's notice. I'm really hoping that I can get a new job soon. But I also know that I will have to come out as a bisexual in my professional life and yes I do feel bad about hiding my girlfriend in this situation.