Apologies, but I must admit ur dad is quite a sharp guy, Sleeping with his wife best friend is something dat makes 4 a gud soap opera.
NOW, let me tell U dat ur mum has bin fooled by ur dad and d oda lady. Ur mum does not have a bestfriend, d other woman has find a place in ur mums arms 4 her to be welcomed anytime at d home th/by using it as an avenue to enjoy wot ur mum enjoys without suspicion.
My dear how long will U see evil nd keep quiet.
Remember History will not show mercy on dos dat sees and refuses to talk.
Tell ur mum - Yes she will get angry and liv, den if ur dad trully luvs ur mum, he will apologise and mayb ur mum can. decide to punish him and at d end both will come bk togeda. - Simple Nollywood movie.
Don't bear such a burden and refuses to talk, instead U are telling ur dad to carry on, maybe some other place. Do dis ASAP.