Kennedy c

I lost my father 4 months ago.I think i am coping with it fine now.But the thing that is making me sick that my mother starting to date people.My mother was cheating on my father for like years ,I knew that but kept it to myself.But now after his death i see her texting this man.she doesn’t know that i know.And I don’t know how to process this information or what to do with it.Should i confront her? Or tell my siblings,but I don’t want to ruin my mothers image.