Caught a women cheating on her husband. What should I do?

So this happened yesterday when I was in my room and a woman(let's call her Y) came to our house. she is childhood friend of my mom. so my mom and Y were having conversation. my mom asked y why she doesn't pick up her calls and Y said she has problem with her phone . So my mom came in my room and asked me if I can fix the problem of Y's phone. When Y handed me her phone, I saw a text message from a guy which goes like "aaj kaha pr ho" then another message from another guy which goes like "aap call kyu nahi utha rhi ho" and after a min Y's phone started ringing and the person who was calling her was a third guy whose name was "Anil" and there was a ❤️ next to his name. I handed her the phone and said idk what issue was and she should visit a mobile reparing shop and after she left I asked my mom what does her husband do for living and she said he's chef in a hotel in dubai and earns and good amount money there but I feel bad for her husband bc her women's cheating on him. Now Im thinking whether should I tell about this to my mom or not cause I don't want to ruin their friendship.