When I started my present job , 4 yrs ago, my co-worker was married to the manager. She left him and is now engaged to the assistant manager. I do not participate in office gossip and did not know that there were rumors of my co-worker and the assistant manager's relationship while she was married to the manager until after she was divorced .She is the main reason that 2 excellent employees have quit. She runs to the manager, her ex, daily with petty issues about other employees . I do not think the manager can be objective . Some days it is very hard to concentrate on my work , but being in my late 50's I am trying to hold out as long as I can. Is there something ,besides quitting, that will change the situation ?

You know what I suggest close your ears to the gossip and rumors in and around the office.
They don't concern you so focus on your job and do what your getting paid to do.Just realize
This office is no different from the next Trust me. Its funny but I myself worked in an office back east New York,I`m around your age now but at that ime I was 18yrs `Listen this was 42yrs early I felt a humiliation surrounded by the soapstars,the cheaters the hustlers,the
Lies and adulterers. I was not only shocked but amuzed by witnessing what I only believed to
See in movies. It had been an awakening for sure.This today is normal,its everyhere

Sounds like a normal office to me, you will find there is always gossip, there is always someone everyone things is a favorite, there is always someone running to the boss with everything.

In some companies they don't let husband/wife or a ex work together because of issues it can cause. But you are there to do a job so just do your job and ignore them as best as you can.