Here is another photo

Recently, my mother began to go somewhere at night, I hear how she returns in the morning and goes to bed, at first I did not understand where she was going, but over time I began to guess that she was fucking with men, it was noticeable in her social networks, I noticed that she writes messages to some men and throws them naked photos, it turns me on that she is being fucked, but she is cheating on my father, what should I do? just to have fun realizing that she was being fucked, or to tell her father?
My father usually doesn't fuck her much, as he usually goes on business trips