What should I do?

Hi. Tell me what I should do. So here's the story. I am working in a BPO company and i have a TL, let's call him Jay. He has a wife and a 2 year old son. I don't personally know his wife but she's the cousin of my live in partner. Mr. Jay has a mistress that is also working in the company and we are all in the same team. The team knows his infidelity but keeps a blind eye. They don't wanna mingle with the affair. Should I tell the wife or should I keep quiet too? I have my evidence with me. My live in partner knows this but he doesn't want to get involved.