Needing opinions from other women with a sister

My sister has always had problems with lying & fabricating stories I recently found out she has been cheating on her partner of 26years, they have 4 children together ageing between 25&10.. I found out that she had a second Facebook so I made a fake account in a males name & added her, seems she has been having an affair for over a year and pretending to go to a job that she doesn’t have.. the new boyfriend is head over heels for her, wanting to marry her etc & she has completely catfished him, told him her children are her step children not her bio kids & pretending she is a veterinarian, she lives in community housing & really works at the corner store.

I decided to confide in her eldest daughter with what’s going on, she has confronted my sister and told her she needs to tell her dad & the other man the truth, but now I feel awful for outing her, have I done the right thing here? What would others have do e in my situation, I couldn’t confront her myself as I know she would just lie to me about it anyway even though I have photos of them together

I know it’s your sister, but her husband deserves to know. As well as the other guy. I would’ve done it too